Exams' in the can. The grades are made, and the horn's in the case. Right? Hope not. This is the time for a few months of stress-free uninterrupted practice that can elevate your playing and make you competitive! Put the pressure on. No one else will. It's just you and these summer days.
What do you want conquered by fall? Brandenburg? Start climbing, but be careful. It's a long way up. Don't fall. And don't get hurt!
Excerpts? Listen to the recordings. Listen again. Then listen to recordings.
Piccolo solos? Practice your piccolo. Play mostly other stuff. Master the horn first. Play the solos later. In the meantime, study the solos.
Poor sight-reading? Play a bunch from the Develop Sight-reading book. You can work on this without the horn probably better than with it. Either way, do it and don't ignore it. You must do this very well on any playing job.
Limited solo rep? Stack your stand with 20 or more solos. Organize your plan of attack and begin.
Horribly slow transposition? Make friends with the 100 Studies of Sachse and Caffarelli. Put the horn down and work the fingers. The problem is page-to-brain, and brain-to-fingers. The lips don't have to transpose.
Crummy attacks? Do thousands of starts. Maybe millions and millions.
Wavy, out-of-control vibrato? Do none and then very little. You have to be able to pierce like a Lazar. You can quiver like a sax some other day.
Awful intonation? Get your tuner, listen, sing, correct.
Bad rhythm? Live with the metronome stuck on on.
Sloppy embouchure? Look at Dick Tracy. Don't be chewing all over the place. Put it up there and don't move. Move inside only. All parts of the lips should share the work load.
Unmusical and boring playing? Check out CDs of great opera people. Sing. Conduct. Make gestures that fit the music. Then sing some more. Don't play boring. Please!
Always playing everything forte? Insist on ppp all the way to fff and back. Do it all. You'll need it.
Clumsy multiple tongue? Open Arban. Go slow and go fast. Do it. Then do it faster. Even faster. Now double tongue scales as fast as possible. How about your chroms? Polish 'em up before September. You may need some valve work done at a good shop.
Crippled arps? Double and triple the arpeggios in Arban. Very fast, no stops. They're everywhere. You might as well master them.
Be your own teacher this summer, or pretend you're being coached by the stars. You don't need to go somewhere, but you do need to go somewhere in your mind and in your progress.