Generally I use a 50/50 blend but recent I made some 60/40 (pg/vg) The reason for the higher PG is because lately I've been using cartos as well as the other "mediums" I'd use... and the more liquid the final product, the better it wicks. I also want to see if it helps the flavor be a little more potent. I know there are people that don't believe that PG carries flavor better but in my experience, it does. I'm no master mixing by any means (the only reason I still buy vendor juices on occasion) so that's just been my experience. I've had 0 luck making 100% VG juice or even high VG juice. The highest I go is 50/50... and it's best of wicking and flavor issues, personally. (I have no allergies/ sensitivities to either Vg or PG as far as I know)