Hint - recycled materials are often the best for this dimension of play. The egg carton that you almost threw away can become the base for a child's homemade elephant; old birthday cards are great for cutting/pasting collages; and canisters are great for making a musical band. Teach your kids to be creative, and they'll find a use for everything. Yes, that's a little frightening, but you don't have to keep the new creations forever...
Dress up magnets
Paint (watercolors, tempera or magic paint books)
Make rubbings (with leaves or any bumpy surface)
Make gift packages
Paper airplanes (not traditional art, but great for young boys!)