We have a crafting playgroup, and I brought the supplies for monster valentines for the kids to do, as well as some cute coloring pages. You can find the coloring pages over here, and the printable for the monster valentines here. I found both on Pinterest, of course.
I was too distracted to get pictures of the setup or while Evan was putting them together. I used little sponges to do the "body" so that I could set it aside to dry without a mess. Once it was dry, I had multiple options for the googly eyes.
I found these really neat stickers to use (here), which are great for kids who are too young to be trusted with glue! Then I also had a pack of normal googly eyes to be used with glue (here). Evan is 3 and is to a point where he understands how to use glue, though he loves twisting it up and down just for fun, but he had fun with the sticker ones too. The only thing I didn't like about the sticker eyes was that they didn't have the same variety of size. I look forward to using the sticker eyes for other crafts too!