Found this cute craft on Pinterest, and we gave it a try last year. It was easy and fun! I found it Momto2poshlildivas.com. She has lots of great ideas for kids, arts, science, crafts, reading, etc. Definitely worth some time reading there!
Supplies needed (I have found all of these at the dollar store):
Cut your coffee filters into heart shapes. You can get a few out of each one, depending on size. Because the filters are so thin, I cut 4-5 at a time. Then let your kids dob away on the filters. The colors will bleed together and give you a pretty tie-dyed effect. We did lots and lots, even the twins participated (though some of theirs had much less color), and they looked beautiful hanging on the windows!