Breaking in One Pocket can be difficult but this may give you one way to start. Since I don't have a table diagram, these numbers will represent balls. The 2, 4, 7, 11 balls are on the right side as you view while breaking.
-----1
----23
---456
--7890
-12345
Lets assume you have the left pocket and are breaking from the right side. The most common break is hitting the head ball (1 ball) very thin on the right side with high, extreme left English. The cue ball then hits the 2 ball and the cue ball goes to the foot rail then rebounds to the second diamond on the long right rail.
The 10, 14, 15, etc., tend to go towards your pocket.
Now the most important part... How do you keep the 7, 11, and 12 balls from going towards the opponents (right) pocket so they have an easy return shot. Actually it's very easy ... most of the time.
Put the cue ball about one ball width from the side rail when breaking. This is the key... make sure the 3, 6, 10 balls are frozen to EACH other. If they are not request a rerack.
Try this several times as a starting point to see how it works for you. All tables play a little different but hopefully this gives you a good start.