Point your rear arm forward in the direction you are going in line with your momentum. Your front arm can be raised up so you are looking under your armpit, or your front arm can be down so you are looking over your shoulder.
The important thing is to create a twisting effect with your upper body in relation to your lower body. An easy way to do this is to cross your rear arm across your torso. It is not exactly necessary to have your rear arm cross your torso so it is pointing towards your momentum, but as long as you create that upper body twist. Once you are in this twisted position, it makes it that much easier to go back to regular because your body naturally wants to untwist and return to the normal anatomical position. Think of it like striking a pose, holding it, and then uncoiling your body to land.
Try to waste as little momentum as possible by not going at too much of an angle and just bashing your baseplate and wheels against the side of the ledge. A little bit of an angle is okay, but not an extreme angle. It’s not like a nose stall, you want to glide. You generally want to be parallel.
As you do them slower, you can get away with not crouching and barely bending down. But as you do them faster, the crouch becomes alot more important.
As you roll up to the ledge, place almost all of your weight on your back foot, and then quickly shift all that weight and pressure to your front foot. This concept becomes alot more important the faster you go. It’s a weight shift from one side of your body to the other. Create that weight and pressure from crouching.
Round shaped wheels help a ton, like classics. Less friction to stick. Square wheels tend to catch and drag more on the side of the ledge.
Wax the ever living shit out of the ledge. Be prepared to have wax on the bottom of your shoes from missing the slide and standing on top of the ledge and the ass part of your pants from bailing and safely rolling with your momentum and ending up with your butt on the waxed parts. Your griptape will probably end up having wax on it too. Wipe your shoes off often as to save your griptape.
All in all:
1. While getting in and staying in the slide, point your rear arm towards where you want to go, in line with your momentum. Create that twisting effect. This makes it much easier to lock into the slide.
2. Rolling up to the ledge, place alot of pressure onto your back foot, and then shift that pressure to your front foot.
3. Uncoil body to go back to regular.
4. Round wheels with narrow contact patches. Put your old worn out wheels to use if they’ve been collecting dust.
5. Alot of fucking wax. Cake that shit on there. On the top, edge, and side. Wax the fuck out of the ledge, fuck it.
Hope this helps.