• 1). Fold a piece of standard 8 1/2- by 11-inch paper in half lengthwise. Match the corners perfectly so the crease is exactly down the middle of the paper. Do this on a very flat, smooth surface to get the best possible fold.
  
  
• 2). Sharpen the crease by rubbing the bottom of a glass or other smooth object along the crease. You want as close to a knife-edge crease as possible.
  
  
• 3). Fold the nose. Hold the piece of paper portrait-style with the fold pointing downward. Take the top right hand corner of the paper and fold it into the crease so the new fold is at a 45-degree angle across the top right of the paper. Repeat with the top left corner. Use the smooth object to make the creases sharp.
  
  
• 4). Repeat by taking the top right edge and folding it so the first edge is lined up against the centerline crease. Repeat for the left top edge. Use the glass or smooth object to make the creases as sharp as possible. For these last two folds, you don't have to use the smooth object to make the crease sharper. A more round crease will have a more airfoil-like shape. If you do crease it sharply, it will fly faster.
  
  
• 5). Fold the two halves together along the centerline crease. Fold each wing down so the edge along the top of the fuselage is parallel to the centerline crease. Now you have an "arrow." If the creases are sharp and the folds are symmetrical, this plane will fly fast and straight.
  
  

Adjusting to Fly Straight

• 1). Make flaps in the wings. Flaps will cause your paper airplane to turn, or if you need to adjust a plane that isn't flying straight, you can use the flaps to make it fly straight. Make a small cut in the trailing edge of each wing about 1 inch from the outside of the wing, about 1/2 inch deep and parallel to the centerline crease.
  
  
• 2). Adjust the flaps. If the plane flies to the right, bend the left flap up slightly. This will cause the plane to correct from flying to the right.
  
  
• 3). Test fly the plane. If it is still flying to the right, bend the left flap up slightly more and test fly again. Continue until the plane flies straight.
  
  
• 4). Curl the wing instead of making flaps. You don't actually have to cut flaps in paper airplanes. Just curl the outside of the back edge of the wing upwards to make it fly in that direction (curl the edge of the left wing to make it fly to the left).
  
  
• 5). Add more weight to the nose. Put a paper clip on the nose of the airplane and it will fly faster and be more forgiving of imperfect folding.