Set the object ball frozen to the rail with its edge aligned with the point of the side pocket. The cue ball is on the long centerline of the table, directly out from the object ball. Play around with this and see how far out you can move the object ball and still make the shot. This will come up in a game more often than not.

Aim for a half ball hit, as you can see in the above picture. I use maximum draw with a half tip of right english. Make slight adjustments in your aim if you miss. Try to keep the stroke (speed and aim) the same. A fuller hit moves the object ball path to the left (shooter's perspective; so to the right in the diagram as we see it). The three rail reverse should be hit pretty firm in order to give it enough speed to come back off the third rail.