Mine are:
Do not shave the same day as applying fake tan
Why? I always shave about half an hour before applying fake tan. If you shave the day before, then you will have a lovely tan - but stubbly legs.
Apply blusher to the apple of your cheeks
Unless you are under 30, applying blusher to the apples of your cheeks can make your face look flat and your cheeks sunken. It is much more flattering to apply blusher to your cheekbones then blend inwards.
Wait for mascara to dry before applying second coat
Why? I never wait and never have problems.
Applying eye liner all around your eyes makes them appear bigger
This is from Bobbi Brown and it's rubbish, IMO. If you want your eyes to appear bigger, then do not apply liner to the inner corners. Instead, apply from 1/3 in going outwards, getting thicker as you go along.
Never apply lip liner to outside your natural lip line
I always go outside my natural lip line. It makes my lips look plumper, especially when I apply it well into the corners. Add a generous coat of lip gloss and almost anyone can have luscious lips.
What are yours?