You can use many rails with your skateboards: from handrails to railings on public outdoor staircases. It takes some practice, so grab your skateboard and get jumping.
Check the rail to make sure your skateboard can slide on it easily. You can do this by placing your skateboard on top of the rail so that the wheels are on either side of the rail, and dragging it back and forth.
Step2
Put some wax on the rail if your skateboard does not slide easily. Any wax will do, like candle wax or even ski wax. You don't want to be in the middle of the rail with your skateboard and have your skateboard stick.
Step3
Set your skateboard on the ground next to the rail.
Step4
Do an Ollie, stepping down on your back foot so that the front of the skateboard pops up.
Step5
Turn your skateboard by doing a half a 180. Once you're in an Ollie, pivot your skateboard so that the front end that's in the air is now over the rail. Your skateboard will now be straddling the rail.
Step6
Shift your feet so they're on either end of the skateboard. This makes it easier for you to keep your balance while you're skateboarding on a rail. During the trick, keep your skateboard on the middle of the rail.
Step7
Do the above from a stand-still at first to get used to the sensation of balancing as you're using a rail while skateboarding. As this becomes second nature, practice using the rail while skateboarding as you're moving.
Step8
Approach the rail head on. When you're very close to the rail, do an Ollie, jumping up in the air. Quickly shift to half a 180, and slide on the rail while skateboarding. When you reach the end of the rail, do half a 180 again so that when you land, you're facing in the direction you're going.
Tips & Warnings
Be safe. Always wear your helmet and other recommended safety gear.