I've figured out how to fold Star Wars TIE fighters. So far I can fold the basic fighter, Interceptors, and the Advanced X1 (Darth Vader's TIE)
Step 1: Body 1
Get a sheet of 8 1/2 by 11" paper, and cut it down to 8" by 11." Fold it in half hotdog-style. Open it up and fold the corners in.
Step 2: Body 2
Fold the paper back up, and fold the tops down. For best results, fold on the lines in Pics. 2 and 3. Fold both sides and both ways. Now, push/pull the far corners in (Pic. 3) until it looks like Pics. 4 and 5. Crease the wings in, like Pic. 5
Step 3: Finishing
To make an Interceptor, follow Pics. 1 and 2: for all wings, fold like 1 and push it in. (like 2)
To make an X1, follow Pics. 3 and 4: for all wings, fold like 3 and push in like 4. Tape if necessary.
To make a basic fighter, follow Pic 5: fold in all corners (except the back one) slightly.