Wash and dry the bottle you are going to store it in completely. Make sure it has a good seal like a canning jar or has a rubber stopper.
Gently crush or "bruise" the herbs, toast any spices, all of which brings out the natural oils flavor of each.
Place herbs and or spices in bottle and cover with oil.
Store in the oil of choice and place the bottles in a dark spot for a week or two.
Strain out the herbs or spices and pour into cleaned bottles.
Heated Oil version:
Heat your oil of choice in a small saucepan.
Add your desired herbs or spices and let steep for a few minutes (until the ingredients are fragrant). If using spices, toast slightly first to bring out their natural oils. Oil temp should be 180°.
Cool, strain and pour into cleaned bottles.