I don't really do crafts unless it's a special occasion or a gift for the parents. I do art almost daily though. I bring out things like paint, markers, crayons, glue, pom poms, stickers etc and let them make what they want with the items I provided for that day. Some of my favourite things for the younger kids are...

-put a piece of paper in a pringles container and add marbles dipped in paint. Put the lid on and let them shake.
-put a piece of paper in a ziploc bag with a sponge and paint on it. They can squeeze the sponge through the bag and not get messy
-hang pieces of paper in your tub and let them squirt paint filled water guns to make a design
-finger painting
-colour wonder markers so they can't colour the walls when I'm not looking

Have fun!!