To set up the line, put a ball on the spot (the 15 in the photo, burgundy stripe), place a second spacer ball in line with the corner pocket, and then freeze the two middle balls to this, with a small gap in between them. The gap should also be in line with the spot and the corner pocket.

The two ball (blue) is frozen to the three (red), pointed past the far side of the corner pocket. Since the cue ball hits the four and then the three in this case, the two ball will throw quite a bit, much more than the six ball. So you can actually point the two and three balls to the far rail and still make the shot.

I align the four and six about to the point of the corner pocket, or just inside. For the standard shot, I put the cue ball 1/2 diamond out from the long rail and 3 diamonds up from the short rail. Aim for a half ball hit on the four with a center ball hit. No need to hit too hard.

To send the left center ball two rails into the opposite corner pocket, this is the setup I start with. The 13 ball (orange stripe) is on the spot and I freeze the three ball to it, parallel to the short rail. The rest of the setup is similar, except I place the cue ball 2 1/2 diamonds up from the short rail and 1 diamond out from the long rail. Same aim and hit.

Finally, to send the right middle ball three rails around the table, I use this setup. Again, the 13 is on the spot. The four ball is aligned with it staright into the corner pocket. Everything else is the same except the cue ball is 3 diamonds up from the short rail and 1 diamond out from the long rail. Plus, aim to hit the three first this time.