Sometimes just getting out craft supplies but providing no instructions can create the most interesting things and can occupy the kids for hours. We do this often and I recommend it.
Austyn experimented with materials to check flex (idea from hockey sticks). Here he put a weight over some different kinds of Popsicle sticks that are glued together to help them stay together tightly while they dry. He is looking under to be sure that they are sitting properly under the weight.
Zoe tends to make puppets, doll accessories, hair accessories and things like that. I didn't get a picture of hers. She made some great stick puppets though.