don't straddle the rail, learn it on a feature where you can comfortably pop on from the side (street rail style), make sure to land on your noses (toe piece of bindings to start out) right at the front of the box/rail and lean forward and most of your weight is on front foot. detuned edges all the way up to your tip will help you out immensely.
if you want to start skierslide then press onto your noses it can be easier to come on lipslide instead so it's noseblunt styles and you are going with the flow.