All the Classics
As face painting is normally reserved for children, looking to them for ideas is a great place to start. Think of an animal that you'd like to be: a cat, a dog, a zebra, a tiger or even an elephant can be fun. Clowns, pirates, princesses and angels are all popular and do not take too much time or skill to apply.
Famous faces
Opting to have your face painted to make you look like a famous person can be hilarious. The party may dictate what people are appropriate, but the thick eyeliner of Amy Winehouse, especially if combined with a wig, is an easy start. The character does not even have to be real. The Joker from Batman isn't too hard to paint, and works especially well on Halloween.
Accessories
You might not want your whole face covered in paint. It may get pretty annoying after a couple hours, especially in a hot room when the paint starts dripping. A good way to still be part of the fun without using excessive amounts of paint is to opt for a painted accessory. Something realistic looking on or near the face, such as a tattoo or a necklace, can catch people's attention.
Don't Stop at the Face
An idea that will definitely get noticed is to paint the body in the same theme as the face. Without nudity, the more flesh the better. If your face is painted as Shrek, why not paint your whole body green too? If you've opted to be a tiger, continuing the orange and black theme across your arms and back can only be more fun and convincing.