Start with a rectangular sheet of paper
Place the paper flat on a surface
Fold the paper in half lengthwise
Unfold the paper
Fold the top two corners down to the center crease
Fold the new top edges down to the center crease again
Fold the plane in half along the center crease
Fold one side down to form a wing
Flip the plane over
Fold the other side down to form the second wing
Adjust both wings so they are even
Flatten all folds firmly
Hold the plane by the bottom
Throw it forward gently