Traditional Boomerang

thingiverse

This is the shape that most people might associate with the term "boomerang", I assume - as in "Australian gift shop". It is a pretty decent flyer. Throw not too low and with little to no layover. If it feels a little sluggish, you might want to try and make it thinner, i.e., scale it down to about 95% along the Z axis. If you just want a printable boomerang that flies well, I recommend starting with [this one](https://www.thingiverse.com/thing:28662). It is a little easier to handle thanks to the tighter elbow angle (more stable flight, easier to catch) as well as the flared tips (retains spin a little better).