I am a full blown, card carrying tank mixer. The only difference is, I do it with tobaccos.
I have 6 Hangsen 'base tobaccos' that I choose from, to start. Then there are 10 or 12 what I call 'complimentary' tobaccos, that are very good, but not what I'd consider a single flavor, all day vape, like the 6 bases. All of the above are in 30 ml bottles.
Then there are a dozen or so 'regular' single flavor mixes, in 15 ml bottles, like maple, toasted marshmallow, caramel, sweet coconut, etc, for times when a little sweetness needs to be added.
Everything is mixed as I would a regular recipe. 60/40 vg/pg, .4 mg nic, and 3 to 5 % flavoring.
I also have some conventionally mixed recipes, that are always mixed 'normally' that are always on hand.
More often than not, when it's time to fill a tank, I'll usually spend a minute and look over the selections, and decide what sounds good. It will usually end up:
3 eyedroppers of tobacco base A
1 eyedropper of complimentary A
1 eyedropper of complimentary B
Then maybe 1/3 eyedropper or so, of a sweetener or a little DNB or whatever.
I have 2 / 30 ml bottles of my 'top dozen' (or so) single flavor mixes (base & complimentary). One 30 ml bottle that I pull from, when tank mixing, and one steeping. The way I tank mix, a 30 ml bottle may last 2 or 3 months. When the one I am pulling from gets down to 5 ml or so, I mix a fresh 25 ml in, put it in the steep rack, and rotate in the new 30 ml bottle that has been steeping. When I rotate in the new bottle, it typically has 2 or 3 months steeping under it's belt.
It's a convoluted, bass-ackwards way, but it just works for me. I've learned over time, what all my flavors 'are' as single flavor mixes. That gives me a pretty good idea of what goes with what. Every tank is a new adventure, a bit of an experiment. I never know exactly how a 'tank mix' is going to turn out, but they always turn out good.
I can, and do mix 'conventionally' for consistency with certain recipes. I just have so much fun winging it. I've never mixed fruits, desserts, bakery, custards, ect. Maybe my style wouldn't work for that. It sure kicks ass for tobaccos though..lol.