sittingbear: I use as a guide something I read online, but I don't remember where, 16 oz. 91% alcohol, + about 1/2 teaspoon essential oil. I say about because you can vary the amount to suit how strong you want the fragrance to be. I find that I prefer less fragrance so it doesn't become over powering. But that's just me, I may be more sensitive to some fragrances than others. You can always add more alcohol or fragrance to meet your needs. Follow the directions carefully, as you don't want to damage the wick stone and clog it up with too much oil. And remember, the fragrance oil you find by the candles in most stores are too oily and not pure fragrance. What you want is essential oil, preferably steam distilled that comes usually in very small bottles, about 1-2 oz. I get mine at CVS as there isn't any other place around where I live to buy any, but you can easily buy them online too. Another option is sites like Caronline's Candles online that sell a wide variety of scented oils like the Lampe Berger brand, but at a much lower cost. She also sells lamps and replacement wicks too. I've always stuck to the original Lampe Berger wicks, as I never have any problems with them. I also keep my spare wick in a tupperware container with plain 91% alcohol in it to keep it clean and ready.
Hope this helps.