We make 2-3 gallons of raw apple cider vinegar every year. We make it by simply pressing apples into cider and allowing the cider to sit in a jar at room temperature for a few weeks, covered with a breathable cloth. I usually use a cloth napkin with a rubber band around the jar where the cap would go. It's that simple. Taste periodically for "doneness." I tasted ours yesterday.
We use our cider vinegar nearly everyday for salads, marinades, mixed drinks, and general cooking. I find I reach for it very often, partly because it's delicious and partly because I made it from our own apples; I didn't have to buy any inputs. It's another tiny step toward #selfsufficiency