I'm a sophomore in high school and I'm having trouble developing an upper range of notes... I believe it may be due to an inconsistent embouchure problem. It seems like my embouchure is never the same and some days I can play high C's like it's nothing then the next have trouble hitting in A. What are exercises I can do to develop my upper range and have it be consistent? How can I make sure I use a consistent embouchure? My director also told me my upper ranger may become easier if I get more of my bottom lip in the mouthpiece because as of now my bottom lip is on the very edge of the mouthpiece and it's how I usually play. I need to work on my range because I'm lead trumpet in my school's Jazz II and I can't afford to just have bad days of playing. I need to develop my upper range and a consistent embouchure. Any advice?