#1 thing to do is make spares and be consistent.
I do my own form of low ball. First game shoot a 10 pin on the first ball, then practice a strike ball or just work on my release for the second ball. Next game shoot a 7 pin on the first ball, then shoot the spare, strike line, or release practice for the second... If 3-6 combos are giving you fits, practice that the first ball then whatever on the second. Don't worry about score or the fact that others around you might not think you know what you're doing. By not trying for a strike on the first ball, you get the maximum amount of throws per game or amount of time you're going to be there.
Getting better at spares will have the biggest impact of anything you'll do. Getting one solid release that you can repeat over and over is something not every one has. After that, work on another release you can throw pretty well when you have to. If you normally come around the ball a lot and cover a lot of boards, work at coming up the back of the ball and going straighter with the same ball, or vice versa.
Telling it like it is.