Use one sheet of rectangular paper
Fold the paper in half lengthwise
Unfold it
Fold the top two corners toward the center crease
Fold the new top edges toward the center again
Fold the pointed top down slightly
Fold the paper in half along the center crease
Fold one side down to make a wing
Flip it over and fold the other side down to match
Make both wings even
Fold up the back edges of both wings slightly
Adjust the wings for balance
Hold the plane under the wings and throw it gently forward