If I were the OP, I'd certainly not try to "cinch" balls on the rail with ONE type o spin. Balls will be on- or close to the rail A LOT of the time in rotation games especially. That means it's a very important shot to master, both in regards to pocketing AND playing postition. If you can only shoot with inside/outside or center, then you'll be at a huge disadvantage to any competent player. Getting the ball to "hug" the rail and such, should not really be a priority. The priority should be to get the ball in the hole, wether the OB lies 2mm's off the rail or frozen to it. Those two shots only appear to be different, but your task is exactly the same, shoot the ball into the pocket.
When you play American pool, you have no idea how much easier your task is, compared to games like snooker. With a soft shot, your margin of error is increased hugely, wheras on a snooker match table, your margin of error is tiny, and the balls simply will not go in if you brush the rail any kind of way, even grazing the jaw (round) will often spit the ball out.
I therefore suggest that you practise shooting the shot softly, but not too softly in the beginning. If you hit it too softly with cut angle, you may not get a clean contact. Start with a stroke that you feel will not give you a "skid" or "cling", but is still soft enough to let the pocket play large. Just play top, or draw to start with to get a feel for the shot. You'll soon realize that the shot really isn't much different, and certainly not more difficult that a lot of other shots. If you shoot it with the right speed, even tough tables will let you pocket the ball very easily. You can then experiment with other kinds of english and add speed as you go along. I think the only really difficult part of the shot is realizing that the difficulty increases a lot with speed, much more than many people think. In a game situation, it's easy to forget this or over-amp the shot due to adrenaline. If your table has been tightened by an incompetent mechanic, or even has old cloth and facings on it, keeping the speed of the object ball down is very important. That is where spin can help you, by letting the cueball move a lot without having to put power into the object ball. Center only- and spin only players limit their games, so be neither.