One of the most common things that young clarinetists hear as they receive their initial instruction in the formation of the embouchure is, "Put your upper teeth on the top of the mouthpiece." The problem with this concept is that it can cause the student to put the mouthpiece into the mouth at an angle more appropriate for the saxophone than for the clarinet. When I've worked with private students who play with the clarinet held at too outward an angle I ask them to think of placing the mouthpiece behind the top teeth. This has worked well to encourage a proper angle. As I demonstrated at the clinic, having the angle too far outward or too straight up and down can cause pitch, timbre, and response problems. Moderation should be exercised; however, if the standard "teeth on the top of the mouthpiece" method has your clarinet students bringing the mouthpiece into the mouth at too severe an angle, try asking them to put the tip of the mouthpiece behind their top teeth.
We had a side discussion at the clinic on mouthpiece patches. There are several schools of thought on this subject. Generally, I find that they help students who tend to have the mouthpiece sliding around in their mouths. The rubber patches also tend to give one a better sense of how they really sound, due to the fact that they tend to reduce the conduction of vibrations through the bone structure to the inner ear. Some clarinetists teach that not using patches allows for better hearing of intonation: one can actually "feel" when one is out of tune. I've studied with teachers of both the pro-patch (David Hite) and anti-patch (James Pyne) schools. They both have valid points. The use of a mouthpiece patch seems to be a very personal thing. I have seen them help my students with the sliding problem and with comfort, but I prefer using a naked mouthpiece, as I find that (for me) a patch can mask a brightness in my sound of which I become aware only when I play without the patch.
Give credit where credit is due, I always say. One of the most amazing musicians I've known is Dr. Donald McGinnis, who was my advanced conducting teacher at Capital University when he filled a one-year vacancy in the Conservatory. Anyway, Dr. McGinnis gave a clarinet clinic at OMEA several years ago and did something that provided a wonderful visualization of the optimal placement of the bottom lip on the reed. He took a piece of paper (clean, of course) and slipped it between the reed and the mouthpiece until he felt some tension. This clearly marked the point at which the mouthpiece curves away from the reed. This is the fulcrum point. Try this and you'll be surprised at just how far down the reed it is with most of the mouthpieces used today. Generally, I find that students are more apt not to place enough mouthpiece in their mouths than the other way around. Listen for the infamous "undertone" sound in the upper register, flatness in the upper register, a thin (maybe buzzy) sound on extremely low notes--these are clues that you should check to see where the student is placing the bottom lip. They could be indicative of other problems, but I've found that lower lip placement is more often than not the cause.
Sure, if they are playing everything below the register break, an incorrect angle or too little or too much mouthpiece in the mouth will not cause huge tuning and timbre problems for the student (or for your ears!!!). Please don't base the embouchure on the low register. It works much better to develop an embouchure that produces good sounding second register notes and use that embouchure down low than getting an adequate sound down low and hoping that it transfers to the second register.
Ah, the age-old question... Without going into all the details, please allow me to suggest that as an OMEA adjudicator and as a private teacher who sometimes has to help students undo bad habits, clarinet students would do well to use the articulation system that my teacher David Hite used to teach:
Articulation really is more complicated than we have time or space on this web page, but Mr. Hite's suggestions to his students all those years ago have helped me to help students who use glottal attacks, who don't tongue at all, or who ease into the starts of notes. Give the three-step process a try not just to solve problems but to help avoid them in the first place.
I took an unscientific, strictly informal poll at my OMEA session on tips for advancing clarinetists on this question. A large number of non-clarinetist band directors have learned this and teach it. I find that if I try to articulate this way, my tongue position suffers, I have to put too little mouthpiece in my mouthpiece, the articulation gets "clicky," etc. My suggestion is to use a point on the tongue that feels comfortable, a little ways back from the tip and aim for a point a few millimeters away from the tip of the reed.
Who? Jean-Pierre Rampal, the great French flutist? Yes. One of the common left-hand position problems I see as a teacher and as an adjudicator is keeping the left wrist too straight. While the right fingers should be roughly perpendicular to the body of the clarinet, the same is not true of the left fingers. A wrist that's too straight will tend to draw the left index finger away from the "A" key, causing problems negotiating the register break and doing things like slurring from throat-tone F-sharp to A. Cal me irresponsible, but I actually (VERY LIGHTLY) rest my index finger against the G-sharp key and use a flute-like left hand position. Many teachers and books insist that one never lean against the keys; however, I find that for me, the spring tension is such that I can "get away with it" on the G-sharp key. I never teach students to lean against the key, but I do try to get them to adopt a more flute-like left hand position: look at your watch when you're playing; hold a tray in your left hand like a waitperson in a restaurant--all of those standard images. Again, call me irresponsible, but if a student does touch the G-sharp key I don't "correct" them, as long as they aren't opening the key.
I also recommend using the concept of a waiter or waitress holding a tray as a way of getting some bend into the wrist:

As your younger students work on left-hand technique, I suggest that you have them slur carefully from throat F-sharp to A, keeping it smooth, even, and without blips or unintended "grace notes." Also the E to A and E to B-flat intervals are helpful. Careful preparation on these intervals will pay off when the student works on the register break.
The point of this question at the clinic was that I tend to see (and hear!) young students underfingering much more than overfingering. I usually ask my students to drop their fingers with weight. Listen for lack of connection between slurred notes or mini-glissandi. if you hear these, ask your student to speed up and maybe firm up the finger action.
One of the questions that came up at the clinic revolved around problems younger students--and particularly smaller students--have with the right-hand ring finger sliding off the hole when the player tries to use the four pinky keys. I suggest making a box with the pinky while concentrating on continuing to cover the third hole with the ring finger (G, F, G, E, F-sharp, G, G-sharp, etc. and then making the box in the reverse direction). I like to use the analogy of geletin with kids. If you have a plate with a square of Jello and slightly move the plate from side to side, you will see the top of the Jello move or undulate a little, but the Jello won't be sliding around on the plate. The ring finger can be like this: the top part will move a little as we use the various pinky keys, but don't let the Jello slide off the plate!
I try to keep this in mind with my beginners and with advanced students, and in my own practicing. Slurring can expose a host of technical problems (weak finger action, lack of finger coordination, and uneven playing). I believe that sometimes teachers do a better job of keeping this in mind when working with more advanced students than with the younger players. Why not, though, get our students started off using the slur as a practice device?
Yes, the Rubank Elementary Method and both volumes of the Advanced Method are my favorites when I'm teaching private lessons to students of the appropriate levels. But, if you use these books, or any books with fingering charts, or stand-alone fingering charts, please make sure that you check how the fingerings are arranged, and try to determine why they are organized in that particular way. Here's the issue: the first fingering for bottom-line E-flat/upper-register B-flat in some charts (including those in the Rubank Advanced) is the "bis" key fingering. Now, I realize that in the French conservatoire tradition the use of the bis key fingering (left-hand ring finger) and the right-hand side key fingering are taught in exacting detail--I own a copy of Eugene Gay's 1932 method book that illustrates this quite well. For our students (who are not studying in the exacting conservatoire tradition), the fact that the bis-key fingering is the first one they see (since we read from left to right) leads way too many students into overusing this fingering. I adjudicated at a solo and ensemble festival in January 2005 and had one high school soloist who played every E-flat and B-flat this way--even the E-flats that were slurred to Cs! It doesn't work. If I had my druthers, I'd probably take the key off and plug the hole. I have from time to time encountered students who were "sold" on the overuse of the bis key by teachers who are saxophonists. The mechanism is entirely different than the bis key on the saxophone--theirs is wonderful, ours is of very limited use. Or, at least it should be...
Although I am a clinician for Conn-Selmer, I fully respect all the reasons people cite for using Yamahas and Buffets, just to name two prominent non-Selmer brands. The fact is, though, that each manufacturer and really each model of clarinet will have slightly different tuning tendencies. The same is true of mouthpieces. And, the issue is not just with intonation, but also with timbre, which is a function of the overtone structure and wave shapes. Differences in intonation and timbre have a huge effect on blend within the clarinet section. No matter what your personal preferences are with regards to clarinets and mouthpieces, if your students are using the same equipment--all other things being equal--I believe that they will blend and tune better. I suggest working with the local music retailer closely when structuring a rental program for your beginners. If the students are all using the same equipment, you can be more confident that you are comparing apples with apples (to use a tried and true cliche) than you can if your clarinet section is a mix of Vito, Yamaha, Bundy, Buffet R-13, and Selmer whatever.
At the clinic, I did not make specific recommendations about clarinets. Yamaha, Selmer, Buffet, and Leblanc all make nice wooden student and "step-up" clarinets that work well. I tend not to be super thrilled with plastic clarinets, but the plastic clarinets of those brands listed above work fine. Just keep in mind the all-important "Rule No. 1" above, though...
I will make two specific recommendations with regards to mouthpieces: the David Hite Premiere and the James Pyne student mouthpiece both work very well and are very cost effective. But, don't mix them -- they have different timbre and tuning tendencies. Try to figure out which matches your concept of what a young clarinetist's sound should be and do try to have all your beginners use the same brand/model of mouthpiece.
Reeds need to be matched to the mouthpiece and the player, so there's not a general rule of thumb I use with regards to "start on a 2-1/2, progress to a 3 in six months," etc. And, keep in mind that reed strengths vary a great deal even within one manufacturer. Here's an example: I play on Rico's Grand Concert Select Thick Blank #4 reeds on my Dan Johnston mouthpiece. I can't use the Rico Grand Concert Select Regular Blank reeds, nor can I play on the Rico Grand Concert Select Evolution #4 reeds. All three of these come from the same company, have the same basic generic name, but all three have quite different measurements and playing tendencies.
After the clinic, I was talking with one of our Mount Union College alums who told me that for his Masters thesis he did a study of ligatures. He found that ligatures affect intonation far more than we might typically suspect. I know that they also affect response, feel, and timbre. My recommendations are the following: Rico's new Harrison-style ligature, the inverted Bonade ligature (when I use these I cut the middle out, but that's another story and certainly is not necessary for your beginners!), or the Rovner ligature. A high school band director friend of mine outfitted his entire clarinet section with Rovners and found an immediate improvement in high register response and a dramatic decrease in the amount of "grunt" or "undertone" on high A, B, and C. They are also much more difficult to smash or otherwise destroy than other ligatures. There are a few disadvantages, but the biggest one is that it is more difficult to get a Rovner adjusted exactly the same way twice in a row than it is with metal ligatures. I think that for most of our students, though, the advantages outweigh the disadvantages.
Adjustable clarinet barrels at one time had the reputation for producing a bright tone. the current generation of adjustable barrels don't seem to have this problem. Some band directors swear by them -- the barrels can help get the section in tune when used properly. Some band directors, however, swear at them -- there's nothing worse than having your clarinet players clicking up and down at random while you are working with the trumpets and them listening to the intonation of the clarinets when you put everything back together. I think that the barrels work fine, but only you know to what extent random adjusting of the barrels might spell disaster in your band. I have not clearly identified a trend, but it seems to me that more band directors have decided that taking the chance is not worth the risk.