You'd be surprised how many challenges to learning the flute can be overcome by following these three simple guidelines.
Use lip balm liberally and often.
If your lips are smooth, the air stream that you produce will be focused and your sound will be cleaner. If you let your lips get chapped, all the little flaky spots and cracks on your lips will interrupt your air stream and create "fuzz" in your sound.
Keep your nails short.
Good hand position requires the fingers to be curved. If you allow your nails grow past the tips of your fingers, then the nails will hit the keys when you play and cause you to use a flatter finger position to compensate.
Swab out the inside of your flute and wipe down the outside of it after every use.
Getting moisture out of the flute before you store it keeps the pads of the keys dry and extends their life, while cleaning the oils from your hands off of the keys and body of the flute keeps your instrument from tarnishing.
What are your rules? Let me know in the comments!