With my family, coleslaw never had a cream or mayo based dressing. When I first asked how to make it, no one could give be precise measurements.
For a small head of cabbage, I'll generally use one small onion and start with a cup of vinegar for the dressing. You just kind of go by the amount of cabbage and by very much by taste.
Wash and core the cabbage. Slice or quarter the onion and chop with cabbage to desired consistency. Thoroughly salt and pepper the chopped cabbage, tossing occasionally, and place in a colander or roll loosely in a clean towel. Place in the fridge for an hour or two to allow the salt to pull excess moisture from the cabbage.
Salting then resting the chopped cabbage is the secret to keeping it crisp, no matter what style of dressing you use.
Place cabbage in serving bowl and drizzle with enough vegetable oil to coat thoroughly, but not dripping with oil.
In a microwave safe container, add a cup of cider vinegar and a tablespoon of sugar. (More if both it's a large head of cabbage) Heat just enough to dissolve the sugar. Take a bit of the cabbage and dip it lightly into the vinegar and taste it. Add sugar or vinegar until you get a taste you like.
Allow vinegar to cool a bit. Pour the vinegar/sugar over and stir. Depending on the amount of cabbage, you may not need all of the vinegar.
Chill thoroughly before serving.
I'm sorry I can't be more precise with measurements.