Here is the diagram for an origami boomerang
If you don't know how to read these diagrams you can
learn.
Moreover you'd better train because this isn't eazy folding work.
This diagram comes from "Pliages en liberté" by Didier Boursin who got his inspiration from Max Hulme. Thanks to Vincent Osele for finding this out.
Use a rectangle of good quality paper (quite heavy but foldable) about twice longer than large.
Fold and unfold in half
Pleat both edges to the center as shown
Crease the central fold and turn the model over
Fold the axis and the folds at 45°
Crease the pleat-Repeat behind Unfold the model
Crease all the folds as shown (valley or mountain) Fold along the horizontal line
Fold in half pushing the square inside the model
Fold completely inside Same as VII and VIII on the other side
Crease both tips
Reverse fold the part on the right inside the model Repeat on the other tip
Fold the remaining part inside the wing Repeat on the other wing