First, ride Epona to Gerudo Valley. Cross the bridge and go to the carpenters' tent. While still on Epona angle to the right and try to go in the right side of the tent. When you are lined up like this, press A to speed up and hold left. If you did it correctly you should be inside the tent without Epona. This will get easier after you get the hang of it. Whenever you enter an area where Epona was programmed to be you will automatically be on Epona since you never really got off. This trick doesn't seem like much but it leads to many cool glitches.