Use a standard A4 or letter sheet
Fold the paper lengthwise in half, then unfold
Fold the top two corners to the center crease
Fold the new top edges to the center again for a sharp nose
Fold the plane in half along the center crease
Make the wings narrow and long
Keep both wings perfectly even
Add a small upward fold at the back of each wing
Press all creases firmly and sharply
Use smooth, stiff paper for less drag
Throw it level with a fast, straight motion
Aim for a slight nose-down angle
Trim or adjust wing symmetry if needed