Other than the aforementioned changes to the forward fin, I've only explored one modification to this airframe so far: A20-1AS "Air Superiority" Skyh...
A fast, long range and fighter jet-style paper airplane, the Skyhunter is a very cool paper airplane to fly.
TAA USAF Designation: A20-1
Step 1: Materials
1 Piece of 8.5 by 11 inch paper
Scissors (for modifications only)
Step 2: Length Folding
Take your paper and fold it in half length-wise.
Step 3: X Folding
Take the right or left corner to the paper and fold it to the length of the opposite side. Then repeat with the inverse arrangement. Then pull the front down to make a doubled layer. Then redo the X Folding, but at the lines, allow the paper to come out from it and pile on top of itself. Then repeat this on the other side.
Step 4: Pulling Forward The Nose
From the outer sections of the cover fold, pull the paper up to the front. Then repeat this on the other side. Proceed to then pull the paper in on itself again and do this on each side as well. Along the top of the section you just folded, fold the nose down. Fold the two separate tabs onto the side which has the repeatedly folded paper, but let the other side go to the "clean" side of the airframe.
Step 5: Tricky Nose Unfolding
Fold the small front triangle to the "clean" side. The open all but the little triangles on the other side so it appears almost as flat as it was.
Step 6: Tricky Nose Refolding
From the blunt front tip, pull the paper forward and then flatten and fold as pictured. The paper will come down on each side to compose two separate layers. Once the front is dealt with begin to fold forward the rear paper. Once you've pulled that forward, two triangles will form, one on each side.
Step 7: Fold The Wings
From about 3/4 of an inch up from the center, fold the wings down. The wings should remain parallel to the trailing edge. Repeat on the other side.