I teach a class called "Make and Throw a Boomerang in One Hour." Actually you make three boomerangs in this class:
1. A light weight indoor boomerang to learn the basics.
2. A heavy cardboard one that flies outdoors in a light wind
3. A boomerang made from heavy polystyrene foam that flies in light to moderate breezes.
All three use the same template. This instructable is for the indoor model.
Step 1: Template
1. Download this template
2. Cut it out
3. Trace around it onto a piece of cardboard. Cereal boxes work well as does the poster board.