Hopefully, these next few tips will help prevent that nasty fallout in the future:
1. Do your eye makeup first, then do your face makeup. That way, if you have to clean up any fallout, you can do so on clean skin and won't have to rub off and reapply foundation, concealer, poweder, etc.
2. When using brushes to apply eye makeup, swirl your brush in the shadow, then tap the handle against your hand to let the loose, excess product fall off the brush on your hand instead of on your face. I do this with almost all powder products (blush, powder, etc.) so that excess product does clump in one are of the skin or fall all over the place.
Brush right after swiping in shadow
Tapping brush on back of hand
Brush after tapping - all excess shadow has fallen off
3. Try using your finger to apply eyeshadow. When picking up product with your finger, excess product will not adhere to your finger, so you don't have to worry about that product falling out on your face. Of course, ALWAYS use your ring finger, as it is the most delicate on your skin, and ALWAYS wash your hands before and after.
Finger swiped in shadow
4. Try using a shadow shield. I picked these up at Sephora a few months ago, but I think similar products are available at other retailers as well. They work pretty well, but are somewhat annoying because there is an adhesive part on one side of the shadow shield and it is annoying to peel off. Plus, this can get pretty expensive if you use them everyday, but might be worth it when doing bright eye makeup or super heavy shadowing.