This has been discussed extensively on onepocket.org. Different people like to play different ways. Here is one way that probably has the fewest issues:
Imagine the score is 7-7 and give each player seven balls to the good.
Freeze the last object ball to the center of the foot rail.
Freeze the cue ball to the center of the head rail.
Breaker picks a (foot) pocket and shoots.
The rest of the game is exactly like normal one pocket.
The last sentence is very important because it covers a whole bunch of rules. For example, it is obvious that you might have more than one object ball on the table, just like normal one pocket.