If you're referring to the down rail in your pic it looks a little scary with how low it si from that angle. I prefer rails I have to suck my legs up to hit. Gets you low and makes misses a little less bad.
For that just give a solid ollie over the rail a few times to get comfortable with getting up and over the rail. Be sure to have a plenty of speed. Then just start cutting back the angle of attack and tapping the rail. From there you progress into looking down the rail and committing to the whole rail. Remember it is more about out the up when you ollie.
2011 Smokin Buck Ferton 155
2013 Flow NX2-SE
2013 Flow Hylite boa
Burton Stagger pants/jacket