Shrinkydinks!!!  Remember these?  They are funny plastic sheets that you can color on and then bake in the oven so that they shrink and harden.  

My sisters and I used to LOVE making shrinkydinks when we were little.  We would work contentedly with our special colored pencils, faithfully cut around each and every detail of our smurf or unicorn or whatever, and then sit directly in front of the oven while Mom baked them for us.  
Such a simple little craft – but SO MUCH FUN!
My husband, who I often tease for saving every shred and scrap for sentimental reasons, saved a box of shrinkydinks for the past 25+ years, knowing that they would one day be fun for his own little kids to play with.  Well, I hate to admit it, but he was right.  Not only was it fun to do such a fun and nostalgic craft with the kids, it was fun to see their reaction to coloring in drawings created by their daddy when he was a boy.  
We still have some left if you want to come and sit in front of our oven with us!

Childhood Flashback