Sort of my sequence doing long tones.
I don't start on C.
My trumpet professor, Gerald Webster, noted that if we start off the day with our mouthpiece and play a middle high, middle low, middle loud, middle soft "natural" pitch it tends to be the same each time. He called it the "Heimatton," and everyone's is individual. I start my expanding long tone sequence with my Heimatton (Eb) and work from there. The high notes don't seem as high and the low notes not so low.