Use a standard letter-size sheet of paper
Fold the paper in half lengthwise and crease sharply
Unfold the paper
Fold the top two corners to the center line
Fold the new top edges to the center line again
Fold the plane in half along the center line
Fold each wing down evenly
Make the wings narrow for speed
Keep both wings symmetrical
Flatten all creases firmly
Add a small upward wingtip fold if needed for stability
Throw it straight and hard with a level release