Kids also love making classic woven potholders. You can find kits online complete with a loom, cotton loops, a hook, and illustrated instructions.
Origami is another mess-free activity. You can find instructions online for folding all sorts of figures, from paper cranes to boxes. Stick with a summer theme and make origami boats that the kids can float in a local stream or pond.
If you don't have a collection of seashells from beach vacations, you can order them online. Kids can glue shells to a drawing or painting, or use them to make decorative magnets, picture frames, jewelry, and plaster beach casts. Check out these other beach-themed crafts and activities.