Regarding the Stamp book, I attended Roy Proper's workshop at ITG in Harrisburg, which was a real eye-opener. He said that Stamp insisted that his students do his exercises along with the piano for intonation. What he didn't say, but in my work with the Stamp book along with digesting what Proper says in his book (I second the idea that you should buy that one as well -- there's also another book explaining the Stamp stuff but I haven't bought that one yet, also published by BIM) I have thought about -- playing along with Stamp at the piano would have controlled the timing. I mention this because the book comes with a play-along CD and I have been doing that ever since ITG this past May and it has made all the difference in the world in my playing. So play the exercises (including the lips-only and the mouthpiece-only work) along with the CD, do them every day and you'll soon notice a huge improvement in many aspects of your playing. Another exercise I have stumbled upon is the Reinhardt "Pivot Stabilizer" as published in Rich Willey's edition of The Reinhardt Routines. Essentially this is an exercise, entirely in whole notes, where you start on 2nd line G, all lip slurs, no tonguing even to start the sound, and slur down to written middle C and back up to G, then rest for 4 beats and repeat it. Then repeat that process with 2nd valve, 1st valve, and 1&2. Then widen that interval to be 3rd-space C down to middle C, and repeat with the same valve combinations. Then widen more, top-space E down to middle C and repeat the valve combinations. Then widen more to above-the-staff-G down to middle C. Once that is completed, change the contour to: 3rd-space C down to middle C up to high C and repeat that with no valves, then repeat that process with the same valve combinations. Then, if you can, slur 3rd-space C down to middle C up to E above high C, and repeat the same process and same valves. And finally, if you can, widen it to be 3rd-space C down to middle C and up to G above high C and repeat the whole process with that contour. It may well not be for everybody, but the whole process takes about 10 minutes and I find that in combination with the Stamp exercises, my range is getting higher and my tone quality (for the first time ever) is staying much more consistent, and I'm also finding that notes which formerly created a mental block for me (A above the staff and higher) are now simply notes to be played and I'm able to concentrate on the music much better.