You would think that a person could run out of things to say about the musical process. And it would be true, except that we human beings continually forget what we've learned, and then we get to relearn and re-encounter ourselves, over and over.
I've had to remind myself of a few things lately; thought it might help you too:
-Clean out your instrument regularly... yes, even you whistle players. Remember to regularly get the gook out of the mouthpiece and to swab out the inside of the whistle when you're done playing, to prevent corroded little bits that will interrupt smooth airflow and make you wonder why you ever thought music would be a good idea.
-Get your instrument looked at by a pro once a year, whether you think it needs it or not. Just like cleaning the fridge.
-Remember to practice playing quietly, with good tone. Most of the time in sessions, we lowly wind players are just trying to play loud enough to hear ourselves over the banjo. And we love those banjos! Sessions are good places to practice playing loudly. Practice rooms are good places to practice playing quietly. (Your cohabitants will thank you.)
-Record yourself every now and then. You're never as good as you wish you were, but often you're better than you think you are.
-Slow down. Set the metronome and play something much slower than you need to, and work on good timing.
-Sit up. Keep reminding yourself to sit up straight for good airflow.
-Stay awhile. Quality over quantity. Pick a tune or two and just sit with them and play them for a half hour sometime, rather than doing bits of this and bits of that. See what happens. (I keep telling myself to do this, and haven't yet!)
-Remember music? It's easy to get in the habit of playing tune after tune at one tempo, at once volume, at one feel. How about putting a little feeling into it? Experiment with dynamics... maybe playing an A part quietly, then a B part more loudly... that sort of thing. It helps drive the music. Get Martin Hayes-ey every now and then.