One of the simplest and cost-effective art activities is craft sticks. Craft sticks (Popsicles sticks) don't cost a lot of money, they come in large packages, and with just a little glue, paint and glitter, you can create anything from picture frames to log cabins.
Beads are another low-cost, easy-to-do craft project. You can purchase bags of colored beads, colored string, feathers and assorted plastic junk jewelry to have students create their own bead necklaces and bracelets.
Finger painting is a fun craft activity that takes few supplies and is something that almost anyone can do. Finger paints come in many colors and can be used to create everything from abstract art to realistic landscape or portrait paintings.
Model clay can be purchased in bulk and is ideal for art activity projects for large groups. Model clay comes in a variety of colors and can be sculpted into ashtrays, busts or just about anything the imagination can conceive.