I like to buy the distillate and make gummies with it. It is normally almost a 1000 mg in a gram. But almost as important as the THC itself is lecithin. This is an emulsifying agent that helps hold fat and water together, and since thC is fat soluble it does not want to dissolve in water but the soy lecithin powder allows it to. Vegetable glycerin is not a bad idea either. The addition of soy lecithin will make your gummies much more potent.
I normally use 5000 mg of distillate per hundred and fifty gummies. That comes out to a little over 30 mg per gummy. Any concentration greater than this does not work out very well, the oil does not want to dissolve completely.