As discussed in this article about ways you can use doTERRA essential oils, one of the most popular methods is topically. The easiest and most convenient way to do this is by making up a roller bottle. It will only take you a few minutes, and you will have a ready made solution ready to go for whenever you need it! See my handy guide below to know how many drops to start with. As a general rule, start with less and you can always add more. Roller bottles can be purchased from many places online. You can generally get sizes from 2ml to 10ml. The guide below bases ratios on a 10ml bottle.