Sidewalk paint/chalk is always fun, also if you paint or do any craft and have left overs, design a craft based on that. My kids have had me to make them newspaper hats, then they paint them and wear them until they are in tatters. You could mix diluted paints from what you have on hand or buy kids' paints. I am always looking for stuff to entertain my precious monsters, but most things lose their interest quickly. My kids' preschool is smart about this; they have the kids paint on a paper, then ask them what shape they want their paper cut into, so they have funky, awesome hearts, flowers, clovers, etc. silhouettes handing all over the walls, and the kids always know which one is theirs. Hope this helps.