As far as steeping goes....
Since I've been DIYing my own juice, I've realized... not all flavors need to be steeped. Depending on the manufacturer and flavor of the flavoring, some taste good straight out of mixing, while others need to be steeped for a month. I've noticed that tobacco flavors almost always fall in the steeping category, as well as any chocolate or nut flavors. Many berry flavors can be vaped instantly, and the custards need to steep for about 2 weeks. I also notice that the PG/VG ratio also affects time, and the times I listed are mainly from a 25pg/75VG ratio. I had to make a mix that was 75pg/25VG (ran out of VG), and it steeped much faster than the VG blend of the same ratio. This is just from my experience.
My favorite juice has been a Guava/Custard flavor. Although I can vape it fine straight out of mixing, The custard really doesn't come into play until it's been steeped for a week. So, if I were to give any recommendation, it would be to buy several flavors from a vendor, and try each one in a dripper or a small tank. Pick the best one, and vape that flavor while the others steep, then try the other flavors after the first is done. Make a mental note, of how long it needed to steep, and figure out which one is better. If you continually don't like the flavor, give it a few months, and give it one more try. If after 6 months, you don't like it, chuck it and chalk it up as a bad flavor you don't like.