When I first started DIYing, I did only single flavors, and then mixed them in the tank to try out different combinations, after I'd tried them singly. But I'm reckless, and soon moved on to making up my own recipes, depending on if I thought it would be good or not. I do small batches for ones I'm not sure about, but if I have something that I know every flavor in it is good, I make them in big batches right from the start. I cook the same way.

I've not made a bad batch of juice yet, though. On the other hand, I've never really tried any pre-made juice that I really didn't like, except for tobacco flavors, which is odd for someone who smoked for over 40 years... but I don't like it, so I don't use tobacco flavor. But anything else seems to be fair game to me.
As far as reviews go, that's all I have to go on. I don't have a vape shop to go to, no one within a hundred miles even knows what vaping IS, and I might think a flavor name sounds good, but if all the reviews say it tastes like gasoline, I'll pass on it. If all the reviews are good, and recommend getting it by the gallon, then I'm going to assume it's probably a good flavor and I'll like it, too. I also don't have an income, and rely on hubby's military retirement and disability, which is very small, so I can't order flavors willy-nilly just to see if they're any good. I use other people's recommendations to guide me. We also have a small farm, and there are cows to be milked and taken care of and chickens to feed and look after, and dogs and cats and everything else, so even if I could afford to buy a small bottle of every flavor, I wouldn't have the time to make them all into small batches of juice to try them out singly. You're absolutely RIGHT that it's the BEST way to do it, but I felt like you were speaking to me in your last post, and I just wanted to explain that sometimes there's a "situation" that doesn't apply to most other people. Like being poor and busy! LOL! So I do it the way I do it, and I'm successfully keeping myself off the smokes, and THAT is what counts, right?
But again, you're absolutely right, so everyone else should do as Capt.Shay says, not as I do!
~Lannie