One fun craft that young kids can do is to make streamer rainbows using cotton balls, paper plates and strips of colored paper. Another is to let them decorate their own artful glasses to wear using cheap sunglasses and gluing fun objects to them.
To make streamer rainbows, cut paper or plastic plates in half and give one half to each child. Give the kids a variety of colored paper strips that are long enough to hang several inches below the bottom of the plate half. Have them attach several of the strips to the front side of the plate using glue or tape to create the "rainbow." Then, let kids attach cotton balls to the other side of the plate to make the "cloud." Use a hole punch to create an opening in the top, then loop a piece of string or ribbon through the opening so it can be hung on the wall or from the ceiling.
For the create-your-own glasses, get a pair of inexpensive sunglasses for each child. Offer a variety of interesting objects such as seashells, sequins, craft poms-poms and confetti. Let the kids use school glue or a glue stick to attach the objects to the frames of the glasses. If heavier items are used for decorations, an adult should help using craft cement. Allow the glasses to dry completely before wearing them.