Following up on my post from yesterday on avoiding chop problems, there are a number of things that combined will help keep your embouchure healthy. One thing I learned to do was warm-down. The summer I learned to do this was the summer I was in the Colorado Philharmonic Orchestra, now known as the National Repertory Orchestra. I was a co-principal horn that summer; every week was a 12 service week with a lot of heavy repertoire. It was a great experience but by about half way through the summer my chops were really starting to suffer a bit. So I made the drive over to Aspen on a day off and took a lesson with my teacher from the previous few summers there, David Wakefield. A major point he made to me then was the importance of warming up and also warming down at the end of each service (a service being a rehearsal or concert) to keep the chops in better shape.
When you are playing a lot it is tempting to not warm up much but it is also especially tempting to not warm-down at all. You are tired at the end of that 2 1/2 hour service and want to get the horn in that case again! But you will set your chops up better for the next service if you cool-down a bit.
Among cool-down exercises out there in print some of my favorites are found in Warm-ups and Maintenance Sessions for the Horn Player by Douglas Hill, available through Really Good Music [UPDATE: The IHS]. About these he wrote that cool-down exercises are
quite useful after a long, strenuous day of playing. Such low range exercises are quite helpful for avoiding a stiff, problem lip on the day after a stressful performance.
The very last exercise in the book he describes as one to “relax all accumulated tension from a long day or a difficult session.” I like his exercises, but pretty much any reasonable set of low chromatics or arpeggios that reach into the pedal range of the horn will do the job. It did help me that summer and I have kept the habit of warming down ever since. Fight the urge to pack up right away and cool down a bit, it will pay off.