Which are you trying to do it on a curb a ledge or a rail

On ledges and curbs you want to avoid doing the 45 degree angles like you would when doing b a front side, try to just jump into it, unlike your front sides when your wondering whether or not to do front foot first or your back foot.

What you need to do above anything else is to keep doing it over and over until you have your own style down, that is really the only way you understand. So keep doing it each day, and remember if u never fall your not trying hard enough man