Use a single sheet of standard letter or A4 paper
Fold the paper lengthwise in half and crease sharply
Open it back up
Fold the top two corners down to the center line
Fold the new top edges down again to the center line
Fold the plane in half along the center crease
Fold each wing down evenly
Leave a small amount of body under each wing for strength
Make both wings the same size
Keep all creases sharp and flat
Use heavier paper for better distance
Add a small upward bend to the back edges of the wings
Tape the nose lightly if extra weight is needed
Throw it level with a smooth, firm motion
Aim slightly upward, not straight up
Adjust wing bends if it dives or stalls
Test and refine the folds for the best flight