Something I do which has become subconscious after so many years was taught to me by hornist, Francis Orval. Believe it or not, Orval was one of the teachers at UTEP while I was there and I worked with him in a number of contexts...the most rewarding of which was the school's large brass ensemble.
Anyway, something he taught me was to take the horn off of the face every opportunity you get. Orval could take the horn off of his lips and put it back on in just one beat of rest. It doesn't seem like much, but when you do this every eight bars or so, it makes a huge difference in endurance.
I don't mean to boast or brag, but I've got great endurance. My reputation in Houston is one of having chops. Kit Reid, one of the most established players in town (and vice prez of the union) calls me a work horse. I don't think it's a coincidence that my friend and trombone player, Ed Lowe, says that playing next to me makes him have to concentrate harder on his counting. He's used to guys having their horns to their faces all the time and he uses that as a cue for himself. But he commented that, when he plays with me, the only time my horn is on my face is when I'm playing. He says that I don't give him any warning. One second I've got my horn down, looking around or whatever, the next second I've got my horn up and I'm playing. When he mentioned it, I explained to him that I learned this from Francis Orval and that I do it on purpose, for my endurance. I'm not saying this is the only thing which gives me good endurance. I'm just saying that, in the context you mentioned, this is what I do.
Of course, I couldn't play like this if I had to "Set" my embouchure. The way I play, I don't have to do any setting at all. I just put my horn up and blow.
Eddie "Tiger" Lewis