Just some random thoughts to throw in here ...
When I started out mixing I took the approach of trying to learn about each flavour concentrate by mixing it on its own first and tasting it. Research the % it needs as a standalone before attempting to blend it with other flavours.
To get an idea of how they blend I would add drops of the standalone juices to a dripper rather than make up trial mixes in bottles. Seemed like a less wasteful way to trial, albeit you don't give the blend a chance to mature. it was possible to see how one flavour could dominate another so hinting at the relative amounts needed in a recipe. Flavours can enhance one another, some kill the other. I wouldn't say it's the ony approach to take, but it's a fun way to play with the individual flavours that you've made up.
When you try a recipe that you've found, try to work out what each flavour is supposed to add to the final taste. If it's not noticeable, ask yourself what it's doing there? Try the same recipe without it. Some flavours are not added for the flavour itself but for mouthfeel and layering, or depth. Some mixers overcomplicate things, I'm suspicious of any recipe with 10 flavours especially when I can only pick out 2 or 3 of them when vaping.
Also when trying a new recipe that contains additives (EM, Sweetener, Vape Wizard, Sour, Koolada etc), mix the recipe both with and without the additive(s). For me, that was the only way to really understand how the additives function and why they were added. If you blindly follow recipes you won't learn as much.
Too many Flavourart flavours in the same recipe = too much triacetin which flattens the result. Blend Flavourart with other brands.
Too many flavours, too much to learn, so little time, patience is limited. I have to wait for the next burst of enthusiasm before trialling again.