Someone mentioned they pre-mix their favorite flavors to simplify mixing their ‘regulars’ which i though was a GREAT idea. One of my faves totals 16% flavor http://e-liquid-recipes.com/recipe/1483479/Strawberry+Delight , and while I’m happy with VG, the jury is still out on the flavours. And given most recipes are all about flavor balance rather than outright quantities, I decided in the quest for harm-minimization to mix at half-strength. At first I had to increase power by a third from (9W to 12W) to get the flavor I wanted, but by the end of the first tank I was back to 9W, and now I can’t tell the difference and am getting all of the nuances plus depth of flavour (Siren 22 30G SS316L 3mm 10 - 12 wrap contact-coil 2’ish Ohms)
I’ve also halved the flavors on this recipe http://e-liquid-recipes.com/recipe/1504165/Sweet%20Cuban with the same success (KF5 Mini same coil and Watts as Siren 22 but 2.5mm 1.8’ish Ohms)
Going to halve both again next refill, see how it goes…
Update - 8% now instead of 16% in the strawberry recipe, going higher makes little difference. The tobacco recipe is now 4% instead of 8%, and going higher tastes over-flavoured - like a little fish-sauce is lovely but too much is awful. My original 8% tobacco recipe is now awful!! 
) Add a bit of brandy, a bit of cocoa, a bit of Irish Cream, 4 different choc., a couple of menthes/mints and a couple of creams… It’s not THAT simple anymore, and I’m only on version 40-something!! 