Start with a standard letter-size sheet of paper
Fold it in half lengthwise
Unfold it and keep the center crease
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 each wing down evenly from the top edge
Make both wings the same size
Flatten all creases sharply
Adjust the wings slightly upward for better glide
Keep the nose pointed and the folds tight