For the last few years, my warmups for playing always are based on the Braun Solos or Bach passages. Then, when I am moving into high gear for French recitals or concerti, I move up in the tessitura and use the Telemann Fantasias as my warm up.
But when I want to review the fluidity of my tone and playing, I return to the technical routines of my youth. And these are not strictly warmups, but rather lengthy, comprehensive reviews of technical patterns, i.e. chromatic, major and harmonic minor scales in all intervals, all slurred, full range. And these cannot be called 'warm-ups' because sometimes they take hours to complete.
I am searching for improved resonance, fluency, responsiveness.
Then I return to the repertoire and see what has changed in my sound and my maneuverability.
And contemplate the fact that there is some alchemical process that welcomes and defies an logical preparation. The act of following any prescribed process leads beyond logic and in the end, it is imagination and the time spent with the bassoon that creates the voice.
The truly ridiculous thing is that I am not really happy EVER unless I have the freedom of time that allows for scale practise once in awhile. Not sure I should admit that.