I had a huge bag of pre-cut fun foam hearts in a variety of sizes that I wanted to put to use. I also have a Sizzix die that is for paper dolls and has different hairstyles on it. One more thing that made it easy is that I have a set of face stamps to use on the paper dolls.
I didn't keep any of them, but for the boys, I just cut off the longer pieces of hair. I let the kids pick their own colors and sizes of hearts to use, as well as their hair style. Some of the hair styles worked best with the heart turned upside down (purple face) vs having the point at the chin.
You can see on the back of the hearts where I cut the holes to insert the pencils and the pipe cleaner arms.
This was a cute and easy craft for the kids. It could be re-created even if you don't have a sizzix. I used low temp glue guns for the kids so that they could put them together themselves without getting burned. This was a 4th grade class, but lower grades would probably be best with assistance from the room moms.
For her Valentines Day card for her classmates last year, I made these "Mustache" cards. I cut the mustaches from stiff felt, and glued them to a sucker stick. She said that everyone loved playing around with their fake mustaches that day!