Gerudo Fortress Skip & Early Spirit Temple Theory:
1) Enter Gerudo Fortress as adult with Longshot (Hookshot will probably work too, but bigger is better!)
2) From the entrance, go as far left as you can (to that large stone wall of the furthest left side, near the locked gate).
3) Do a Hookshot Clip through this stone wall and propel yourself to the ladder that is behind the Gerudo guard that blocks the gate. (I don't know if she will bust you or not. She probably will, which would disprove this theory.)
4) If you're not busted, do an DJ off the ladder and go to the other side of the gate.
Tada!
Method 2:
2) From the entrance, go as far left as you can, or you can stop at the front of the stairs. Propel yourself to the flagpole on the left side of the stairs (your left).
3) Once on that cliff, do the BEST DJ you can do (Bombchu may be required) to get as far back as you can. If done right, you should end up on an invisible piece of floor that is above the stone wall.
4) When on this invisible floor, walk while targeting your Hookshot/Longshot so that you don't fall off. When you reach the edge closest to the locked gate, try do a running slide with the Hover Boots. Hopefully, you will land either on the center of the gate or beyond the gate.
Tada!
I can't test this because my little brother got a hold of my 3DS and overwrote his file with mine, so I have to start ALL over
, but I will test it once I can.