Wanted to simulate a Peppermint Patty for a friend. The Double Chocolate is what I had on hand to start with and it seems to work well at this ratio. The Creme De Menthe is the creamy mint portion, and the Koolada is the the cooling sensation on the exhale. The sweetener is there as more of a binder than anything else, not sure why but without it the mint is very strong and the chocolate doesn't come through as much. I played with this for quite some time before coming up with the final blend that works well as a shake and vape but is great after about 48 hours.
From @Queuetue : The Derringer is my choice for testing, in a mix or with a single flavor. Please support creative people by buying authentic atomizers, but I also keep a number of these clones from Fasttech on hand so I always have a an atomizer ready to go while I'm mixing.