When i mixed a tequila liquid I used 4ml 24mg liquid, 1.1ml of VG and .9ml of tequila. The mix was perfect. Plenty of vapor and plenty of tequila taste. Remember though, you can still get the bad side effects of alcohol from an alcohol liquid. I had to dump mine because it raised my BP to a very unsafe level. Alcohol is one of my blood pressure triggers. I can't even take Nyquil,lol
And yes, if you use that much gin to get to 16mg, it will be way to thin. You need some VG to thicken it up a bit.