I think this project contained enough new ideas with enough old ideas--Lily enjoyed it :)
I busted out some coffee filters and natural markers (I'm sure Crayola or whatever would work fine too). She enjoyed coloring on the coffee filters, I think, because they were different than normal ol' paper. Then I swapped out the markers for a paint brush and small glass of plain water and let her go to town "painting" the filters. This was also a hit! She enjoyed having free reign of the paint brush, and I enjoyed not worrying about where "paint" could get flung.
When she was done I set them flat on the kitchen counter to dry, and once they were dry I cut heart shapes out and glued them to "cards" (i.e. white computer paper that I signed her name to). Valentine's cards--done!