I used to brace the needle against my chest or stomach to help push off the stitch.... until I BROKE a needle and dropped a bunch of stitches! I'm not sure how I started doing this, either, but I fixed it by only only only using my finger or the RH needle to slide the stitches off the end. I still catch myself every once in a while... but broken needles and holey clothes shoul dbe incentive to stop!
My other bad habits:
Sticking the needles in the ball of yarn... then I complain when i get to a part in the yarn where it's split. I'm getting better at this, especially since I started winding everyting into center-pull balls, but I still do it.
NOT PUTTING THE SCISSORS AWAY PROPERLY... then I implale myself when reaching in the knitting bag.
This is like knitting therapy... purging ourselves of our naughtiness!!!!!