If you have never used whistle tones as part of your warm up, give it a try! I find it incredibly useful to relax my embouchure after piccolo playing, and to further increase embouchure sensitivity overall. One must be VERY relaxed to produce these tiny sounds: if you get a lot of air instead of the pure sound, you are blowing too hard. I use the "Chimes of London" tune, from Peter Lukas Graf's Flute Tune Up book. It is a challenge to hold these tones perfectly stable: feel steady air pressure behind the notes and a stable support under the air column. Happy New Year... and happy whistle tones!