Welcome Daniel
That is the $1,000,000 question for all DIYers. You will get a variety of opinions, so I'm going to go from my personal experience.
I do a lot of TFA mixing and I do tend toward higher-flavor percentage mixes. Based on what I read in the TFA
thread (
The Flavor Apprentice Flavoring Thread | E-Cigarette Forum) most of the mixes don't need a lot of time before
vaping. I'm pretty impatient when it comes to mixing. If I'm making a flavor, it's because I want it NOW
However, over and over, I read that tobaccos need some steep time - as do some vanillas - in order to let the flavors come together and meld well.
There are other proponents of "mix and let it sit for a few days/weeks". Usually, I do "steep", but not intentionally. I'm often mixing 60-120 ml of different juices at a sitting, and since I'm only making for myself, stuff is going to sit for quite awhile before I get to it. I vape maybe 4-6mL/day, and I always have about 30 different flavors at any given time. (I'm too tired to do the math on that

)
I just know that almost any juice I make, I can load a tank and be happy right away.
My best recommendation is to make two smallish bottles (5 or 10ml?) One for immediate use, and one to set aside for some time. Do your own comparison as to what you like when you like it. Make sure to date them (which I'm not good at doing, so I don't know how long any of my stuff sits around!)
Looks like you have enough posts in - come on over to the DIY forums! Hoosier, DannyV45, and Bill's Magic Vapor all have amazing blogs of information for new mixers
