What he said pretty much. You have to come at an angle and then sit down on your back leg. It's important to not get your weight too far on top, you sort of push from the heel and lean back a bit, if that makes sense.
Speed is key for length of course, but you can start with learning to pop out in the middle and then go faster as you get more comfortable.
They can be really sticky on "stones", granite, marble and such, but it's usually pretty easy to grind on angle iron.
Go get it!