Remember to play sitting at the edge of your seat with your feet flat on the ground.
Breathing: practice the inhale technique where you put your hand infront of your mouth and inhale quickly in a way that makes a sound like wind. Keep working on breathing through your mouth while playing, and be sure to focus on feeling your lower abdomen and back expanding when inhaling. Feel breathing and starting a note as being part of the same gesture, like the wind up and release of throwing a baseball.
The Common Denominator:
Use this piece as a way to work on long tones and controlling your air. Remember to take a full beat to breathe at the end of the whole notes (where needed).
Home on The Range:
If you are feeling tension in your sound production, sing to undo the tension and return to the horn. If you are finding that you are struggling partway through a phrase, add in an extra breathing mark; most hiccups in brass playing are at least partly fixed with more air.