My biggest problem with front-crawl (freestyle) swimming is that I naturally kick four times per cycle (i.e. twice per hand), such that I'm always kicking with the same foot when a hand enters the water. This makes my body roll worse on the left side, and I find it very hard to breathe on that side.
I guess that learning to kick two or six times per cycle (i.e. once or thrice per hand) could improve my technique a lot, but I'm finding it very hard to get the hang of it. I can start out fine, but after a few strokes, I'll take a breath and then either go back to two kicks without realising, or lose my rhythm entirely and start waggling my feet in an unco-ordinated way.
With two kicks per stroke, I feel like it's making me speed up my strokes to keep my legs from sinking between kicks; OTOH, with six I feel like I don't have time to fit all the kicks in.
Apart from "just keep practising", how can I change my kick pattern?