Ahhh, camp crafts. Many of the best summer camp crafts are mess-free, portable (great for indoors or outside), and repetitive, capturing kids' attention for hours. Friendship bracelets are a prime example. Stock up on colorful thread
and beads, and let your kids try their hand at all these different friendship bracelet patterns
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.