The Professional is a paper airplane design described in the "The Klutz Book of Paper Airplanes" in 2004. It is a delta-wing style plane. A key to successfully folding a paper airplane is to be as precise as possible with your folds. In other words, fold the paper exactly as described. Another key is to make sure that when you fold the paper, make the creases as sharp as possible. By making precise folds and sharp creases, your paper airplane will fly farther and more accurately.
Holding the paper in front of you so that it is longer from top to bottom, fold in half, from the bottom to the top.
Take the top right corner of the paper and fold it down to the bottom of the paper. Then take the top left corner and fold it down to the bottom as well. When you are finished, the top sheet of the paper should now be a triangle.
Fold the bottom right corner up so that the corner matches up to the top of the triangle. Do the same with the bottom left corner.
Unfold the last two folds you made. Fold the bottom left corner so that it lines up with the crease you just made. Do the same with the bottom right corner.
Leaving the corners you just folded where they are, refold the corners as you did in step three.
Turn the paper over. Holding the paper so that it is longer from side to side, fold it in half from the right to the left.
Take the top half of the paper and fold it back, starting about an inch from the fold on the right. This will be the right wing of the airplane. Turn the paper over and do the same to the other side, making sure that both wings match up perfectly.
Unfold the wings halfway so that they are flat across the top of the plane. Fold up about half an inch of paper from the tip of each wing so that they are standing perpendicular to the wings.
Drag your nail across a fold when making a crease will help make the crease sharper.