1. Most foundations wil look darker in the tube, bottle etc. than they will on your skin. Test the foundation on your jawline before buying to make sure it is the same color as your skin.
2. Don't use foundations that are too light and make you look ghostly.
3. Don't put too much on - the foundation shouldn't be visible.
4. Make sure you don't have a foundation mask ( when you can see where the foundation ends).
5. Mask regularly so you won't have dead skin that shows up under the foundation.
6. Keep foundation looking natural.