I find "being musical" is a very difficult thing to just turn on and off like a light switch. And I have yet to meet a single student in 25 years of teaching who was very good at that either.
So even "just" the drills and basics need to be done as musically as possible 100% of the time.
I sometimes like to visualize one of two things to help me with this:
- I am broadcasting the drills to Facebook Live and soliciting honest feedback
- I am recording the drills for a recording to accompany a method book
Do you think Sam Pilafian and Pat Sheridan had to be reminded to focus when they were recording the accompaniment to The Brass Gym? First of all, they are always concentrating to a high level. But even still, the threat of shipping to the world a recording of you playing your own exercises poorly is a good way to get you to focus.
How do you focus when you are "just" playing drills and other basics? It's what separates the truly great players from the good ones.