I did mosaic mirrors with that age range once. We glued a small mirror in the center of a piece of thin plywood, glued chunks of broken pottery, glass marbles, buttons, whatever (it's good if everything is the same thickness), around the edges. Then I did the grouting for lack of time. Put sawtooth hangers on th eback so they can be hung.
Or you could do mosaic stepping stones or a mosaic bird bath (using a shallow flowerpot as a form - make sure things using terra cotta get stored inside over the winter so they don't crack if absorbed moisture freezes).
You could decorate canvas bags (dying, painting with fabric paint, gluing things on, sewing things on).
Weaving. Even if just doing those potholders out of those loops, it's something that adds to a person's base of knowledge. But you could do woven wall hangings or something else small (because it is time consuming, best to keep the project small). Beads can be used in the weaving.
Mobiles using whatever your group fancies. Could be those wooden shapes from the craft store painted with photos glued to them. Could be origami creatures.
Seed pod people. Gluing whatever pieces of nature (twigs, pinecones, seed pods) that you can find together to make people or animals.
Mom to unschooling 4everboy since 8/01