This is only a simple step up from your bog-standard 50-50, but looks about a million times more steezy, specially when executed like it is by Jamie Nicholls here. You can get a more detailed breakdown of how to do the trick here, but really, it’s pretty simple.
1) Approach with the rail on your frontside with a decent amount of speed.
2) Pop onto the rail and shift your weight over your front foot. Move your hips forward rather than just leaning the top half of your body over.
3) Keep your weight over your front foot, and keep your eyes on the end of the rail. Pop off the end and ride away.