Hi there
strat-pat.
OK well first off...what's the nic strength of your e-
juice? And where did you get the vanilla flavouring? If you bought it from
Happy Vaper, or
Perfumer's Apprentice...yay. If you bought it in a grocery store, forget it. Anything flavourings you'll find in a grocery store are far too weak/unconcentrated for e-
juice purposes.
Those questions aside, your idea points out one of the problems with premixed e-juice, & one of the reasons I recommend DIY instead. Anything that you add into premixed juice is going to dilute the flavour & the nic that are already present. Without going into too much detail here...the simple fact is that altering a premixed juice is
way more complication than it's worth. DIY from scratch is super simple - you know exactly what your flavouring & nic levels are, VG amount etc. Altering a premixed juice...headache.
Anyway, assuming you have proper flavouring...if you really wanna give it a go, & don't mind the tobacco flavour & nic being diluted...I'd recommend putting 57 drops into a smaller bottle (a dram bottle ideally, so you don't end up losing your whole bottle in case you don't like the results) & adding 3 drops of vanilla flavour. That'll mean 5% of the juice is vanilla flavour.
In e-juice, 10 to 15% is the most common range for flavouring percentage. Sometimes if the flavour is fairly weak, kicking it up to 20% is recommended. If it's a super strong one, sometimes 5% alone will do. Since your juice is already flavoured with an indeterminate amount of "Lucky Strike" flavouring...5% vanilla added in should be fine. If that doesn't get it done to your taste...you can try again with 54 drops of juice + 6 drops of the vanilla.
I'll PM you if you like re: DIY...I've helped a few folks get the hang of it.
EDIT: 36mg?! Geez...that's a
much higher nic strength than most people vape. My advice would be to cut it down to somewhere between 18mg and 24mg...using plain PG or plain VG. You can figure that out using this free e-juice calculator:
todmuller.com/ejuice/ejuice.php
Just enter your Initial Strength (36) and your Target Strength (between 18 and 24). Then enter the Batch Size. Ignore the stupid part about water, lol. If you want to add Vanilla flavour, enter 10. Then click on the screen...and below it'll tell you how many drops of plain PG or plain VG to mix in with your juice, as well as how many drops of flavour.