It also keeps your body super-hydrated and therefore works to prevent drymouth. In addition, it also gives you something to do and can have a calming effect on you if you are a little nervous. This routine keeps your body moving and the cotton out of your mouth. Drink water only. Keep away from soda, tea, coffee, milk and other drinks that will stay in your mouth even after you brush your teeth.
Water is the perfect drink.
Learn to like it. Concentrate on your goal. Keep looking at music, playing the excerpts in your mind, not on the trombone. It may help to write some thoughts down. Don't try some new breathing place or interpretation you overheard someone else use.