I've had students whose flute's footjoint has slipped right off the flute while they were playing and onto the floor!
And my own flute (actually, my old flute, that got stolen out of a car...) used to have such a slippery headjoint that I couldn't hold the flute by only the headjoint! Otherwise the whole flute went crashing to the ground...
Here's an easy solution for you. Actually 2 solutions.
That's right! 2 easy solutions for the price of 1! (Wait... Free + Free = Free...) I like FREE by the way. I hope you do too :)
Candle wax fixes most issues like these above. And cigarette paper can most of the rest.
If you want more demonstrations of proper (awesome) flute technique, let me know below and I'll send you more goodness every 2 weeks.
If you add your email below, not only will get more of these superb teaching bits of awesomeness, but I'll keep you updated about how to get into this course...