As a former second grade teacher, whenever I had parties, I liked to have stations so the kids could do activities in small groups. For example, I might have a station with a Valentine craft, another station where the kids could make a Valentine card for someone special, and another station where they would decorate the cookie and then pass out their Valentines. The kids would rotate when you play music or ring a bell. Oriental Trading Company has inexpensive craft activities. You can do a whole group activity like reading a Valentine story or playing the Bingo game and then break up into stations. Near the end of the party, you can serve refreshments and the kids can open their Valentines.