One of the things I tripped over is the "dead tongue" syndrome. When first starting to vape, I obviously tried premixed
juice from vendors. Good ones were good, and bad ones were bad, but all were new to my tongue.
Once I started mixing my own, I'd try a mix, and if I didn't like it, I'd add a drop of this or that, and try it again as soon as I felt if was steeped long enough. I'd hardly ever throw anything out. What I ended up doing was killing my taste buds for that
juice. I find that regardless of where the juice comes from, I need to rotate my juices to avoid that dead tongue. It's a lot like when you first start smoking real cigarettes - what a burst of flavor - but after a period of time, the flavor is gone and you just go through the motions.
So to give any mix you attempt a fair chance, make sure your tongue isn't remembering that last juice before you corrected it. Once you get it right, it'll be obvious you have it right.