Well, first it depends on the rail. I personally find switch toes over easier to pop on and lock on (most people are like this, but there are a few that prefer tails over). So whether or not the rail is urban (so, even if it's a "ride-on" rail) approach looking over the shoulder of your dominant/front foot (so if you want to be right foot forward, look over your right shoulder) and approach from the right side of the rail (well, it would be the right side if you were going forward...and this is for right foot forward, for left foot forward it would be the other side). Then, pop, if it's a "ride-on" rail you don't have to pop too hard, if it's urban you have to pop hard enough to get your tips over the rail, once you pop just turn your body and lock onto the rail. If you want to try tails over, same method of approach (looking over your front foot shoulder), but this time from the other side of the rail, so now your head is farther away from the rail (unlike toes over where your head is right next to the rail) so for a little bit you'll be kinda blind to the rail. Now, pop, I usually pop slightly off my toes so I can get my tails up above the rail, I also come in at a slight angle towards the rail, get your feel centered over the rail and slide it like normal. Hopefully that makes sense, good luck.