I don't use a starter. Cabbage naturally has the bacteria needed to ferment it. The key is adding the right amount of salt such that the environment is inhospitable to other bacteria while allowing the fermenting bacteria to grow, but not making it too salty, which would interfere with the taste. You sort of know when it's done fermenting by the smell. I suppose there's no right or wrong way to do it, you can ferment it lightly or ferment it a bit more strongly. I don't have a set recipe that I follow. I was shown how to do this and so that's sort of what I do. Also I suppose how finely you cut the cabbage makes a difference. If you cut it in huge chunks like I see with kimchi that will take longer to ferment. If you want it to ferment quickly then cut the cabbage really finely.