To start I get fresh cabbage either from my garden or from a farmers' market. I have tried store boughten cabbage, but it doesn't turn out as good. Then I slice it to about dime sized thickness and depending on the size of the cabbage, prepare about 1 head's worth before salting it with approximately 1 tablespoon of non-iodized salt per pound of cabbage (it's kind of subjective but I go by taste with no exact measurements). In a stainless kettle I then beat it and knead it with my knuckles until the salt and beating action brings out the moisture (and makes my knuckles sore)... There should be plenty of liquid covering the beaten cabbage. I usually end up with about twice as much liquid as need to cover the cabbage once it's in the jars. You should never need to add water.
Then - and this is where my recipe differs from most; I put the cabbage directly into the canning jars and use a wooden spoon and it's handle to poke down and pack the cabbage tightly into the jars leaving as little air space as possible. The idea is to get all of the air pockets out of the cabbage in the jars. Then I tuck a couple of large outer leaves of the cabbage that were saved to tuck the cabbage in and keep it under the liquid. The large leaves should be right at the top of the rim of the jar. Then I put either large marbles or a smooth river stone (approximately an inch diameter or so) on top of the top leaves. The stone or marble(s) should stick out above the top of the rim. Then I put a canning lid on it and tighten the ring down moderately tightly making sure there are no cabbage shreds between the lid and the rim to make a good seal. Since the jar was filled to the top, some of the juice will come out as it's tightened. The idea is to make the lid push down on the stone and cabbage to keep it under the liquid as it ferments.
Then, put your jar(s) in a cake pan out of light and at room temperature and forget about it for a week or two. The jars will bubble and leak and if you've tightened the lids tightly, the lids may even bulge a bit - that's ok. In a week or two, you may want to open the jars and check to make sure that everything is still under liquid. If not, it's because there was still a bit of air that wasn't purged out when packing the jars or a poor seal. Pour in some salt water to refill the jar(s) and tighten again (I usually save some of the salty juice in the fridge from the smashing process for just this contingency). While you're in there, give it a taste. Depending on your particular tastes and the storage temperature it will probably need a total work time of about a month to 6 weeks. If it's in there too long, it will get mushy.
When it's done and ready to eat, the first thing you will notice is how crunchy it is, and then the flavor! When it's just right, stick it in the fridge to stop the fermentation. It should be good for a year.
Generally, the only ingredients are salt and cabbage. Sometimes I will add horseradish medallions or even prepared horseradish, maybe some caraway seed when packing the jars. The big thing with this recipe is that it's so easy and trouble free - it's already in the jars and ready to eat!
A note to add: Since the jar rings have been steeped in bine for a month or more, it might be difficult to open the jars due to rust. You might even have to cut them off. Just replace them and clean the jar threads of the rust and you're good.