yes, you can use any suppliers skin-safe fragrance oils. FCO is a great oil to use with a very long shelf life. You wanted to add a 3rd ingredient: cyclomethicone is VERY poplular. It is an oil that once rolled or sprayed on, becomes dry(dry oil sprays, dry oil roll ons, etc). If you choose to use FO, FCO & Cyclo, there have been alot of threads on this one....I should know, I've asked alot about this. Here is what I've gathered(& used myself, after much experimenting): 7:1 ratio or 6:1 ratio, broken down into "parts"(ok, here is where it used to confuse the heck out of me...the "parts". Another confusing thing is that these %'s are for larger than 1/3 oz size. I have yet to figure that out. The only thing that has worked for me, is to make at least a 2 ouncer & then pour that into rolller bottles. My problem is that most of the time, I just need to make ONE 1/3 bottle in a particular scent. So if I make 2 ounces, just to get the measurements right, I have a ton of leftover/waste after pouring it into the ONE 1/3 roller bottle I needed. ) Ok, back to the %'s: 7:1 ratio or 6:1 ratio, broken down into "parts" (let me cut & paste from a source): some people use less or more, but here is the standard recipe: 1 part fragrance oil to 6 parts cyclomethicone it depends on the size...whatever it is, break it down to 7 parts. example : for a 2 ounce total weight - 2.0 divide by 7 = approx .28 per part. so you would use .28 fo and the rest is cyclo. 2 oz dry oil spray - .28 oz fo 4 oz dry oil spray - .57 oz fo 6 oz dry oil spray- .85 oz fo 8 oz dry oil spray - 1.14 oz fo IF you are adding FCO, just substitute one of the cyclo "parts" with FCO. I truly don't know what the proportions would be to use only FCO & FO. But since you said you were looking into adding a 3rd ingredient, I think Cyclo would be great. (sold at aromahaven, bittercreek, wsp, the sage, etc.. HTH But there are a few threads on this subject here....search around under FCO, roller bottles, etc....