Natural oils

Use a base oil. Any kind works.
As for making the oils, the easiest is the Cold Method, in which you mix equal parts dried herbs and oil together in a jar and let it sit in a cool, dark place for 4-6 weeks (shaking the jar daily.) After that time, you strain the oil into a new jar and store it the same way (the Sun's UV rays break down the oil.)

With the Hot Method, you have two choices: stove top or oven. Oven is preferred, as it makes a higher quality (i.e. medicinal quality) Oil. Preferably, have your herbs powdered down, mix them and the oil together in an oven safe dish that you have a secure fitting lid for. Bake in your oven, at its lowest heat setting, for 6 hours or so. Once it is cool enough to touch, strain the oil into a jar with a tight fitting lid and store in a cool, dark place.

For stove top, just heat the oil and herb mix together in a non-aluminum pan until you start to smell the herbs. Remove from heat and strain into jar