Aaron Letich has provided an excellent post on methods of making your own Oil of Abramelin.
I use this oil in just about every single rite I do. It has consecrated all my tools, the candles I use to represent the Light of God, and myself. I bought mine from Soma Luna years ago. I got two ounces, and I don't think I've used a single ounce yet. A little goes a LONG way.