i used pre-cut and pre-folded cards from american crafts, rescued the toilet paper roll from our recycling bin and grabbed some crayola finger paint i have on hand for moments just like this. i demo'ed the stamping for jack exactly one time before he was ready to try it himself -- and he wouldn't stop! he LOVED stamping hearts. i made him stop after a few on the cards but let him go wild on some old newspaper.
then i dressed the cards up a little bit with some washi tape and patterned paper. naturally mama has to get in on this crafty action :)
my little "helper" -- he made a mess while i got crafty. thanks buddy!
this whole project took way less than an hour, start to finish (done in our pj's, no less!) -- and now i have super-cute handmade valentines to send to the grandparents. score!