There are many ways to do this
A) 1) You can skate parallel to the curb bench bar ect.
2) Ollie up to the Object.
3) Land on it with one truck and put weight towards the front so the back lifts up and rests on it, or just land on it with both trucks.

there is another way to do the 50-50 grind, doing the grind this way makes it a little easier to do other tricks also and you wont always mean to.
1) first find a shift in pavment that is about 6 inches high. (for ex. at a park near you you may have a snack bar on higher ground than some other pavment.)
2)Put you pole orany old pole you find laying around dont on it in a litle crack(you can bash the crack in with the pole.) {dont have the pole ontop of it so you have to ollie up it or else that would be the same as the 50-50 to the left}
3) ride straight on to the pole and just grind straight down it.
You may fall to the side