I don't know if I saw it on reddit but there was a list of all vendors and flavorings, and their perferred range of % to start them out on.
Flavor reviews and ATF
OP - this is the correct answer.
Individual flavors are best used at different percentages, as examples - the range for TFA flavors ranges from .0005% to 12% or more. For INW the range is .1% to 6% or more. FA normally ranges from .1% to 3% but there's probably a few I've never used that are considerably weaker. Using ten times the flavor you should, you're not gonna have a good time.
Tfa ripe banana taught me to check percentages haha. That shit tastes like chemical ass at even 2%, I used 10% on my first try with it hahaha.
Alltheflavors has statistics for that average % used and a graph showing how it's spread. That one's your best bet for researching.
Lots of All the Flavors fans here but there's another place I look too. E-liquid-recipes has an average used single flavor and another average for amount used in a mix. Ya might want to check it out and register your concentrates there as well.
Those percentages aren't really to be trusted
I agree with the others, alltheflavors.com will show you on the flavor's individual page. One you get to that page, have a look at the recipes too and sort them by highest rating. The top recipes will give you an idea how much to use in a mix as well as what other flavors it may work well with.
I search the flavor list at ELR and divide the average by half if I want it strong.
Presumably you meant 'in half' (which would result in the strong flavor) and not 'by half' (which would result in using 5x as much as you should normally.)
I've found the proper way (for me) to figure how much of any given flavoring will work is to test each flavor starting low and increasing. While testing I make very detailed notes for each flavor. What may be optimal for one can be crap for another. Too many rely on others experiences for how much flavoring should be used. You need to have confidence in your own abilities. I just read "all this" and...I got a really good laugh!!! Do not make the assumption everyone here knows what they are doing. You need to figure out what works for you...just like you did (hopefully) with whatever vaping setup[s] you use. Sorry I couldn't be more helpful...but I am being honest.
If I may offer an example...
Take a look at Single Flavor Testing Pt1 + Pt2 by ConcreteRiver.
As C-Riv notes: "Getting familiar with your flavors is the single biggest step you can take towards being able to quickly develop recipes."
Pt1 https://www.reddit.com/r/DIY_eJuice/comments/86od1l/faq_friday_single_flavor_testing_part_1/
and
Pt2 https://www.reddit.com/r/DIY_eJuice/comments/8dsu5d/faq_friday_single_flavor_testing_part_2/
C-Riv has figured out a system that works for him or her.
Isn't that the ultimate goal for each of us?
I do believe what you are really asking is what should be my optimal starting point with any given flavor. The only way for you to know that is to test each of your flavors and get to know them for yourself. That is how you will find what is optimal for you.
There really is no shortcut or cheat sheet to knowing your flavors!!!
I SF tested Holy Holy Grail RY4 at 10% and now it scares me. I will never get that taste out of my mouth. Definitely check ATF for average percentages first and check the sidebar here for flavor reviews. Be weary when you get advice from people that say to start at a certain percentage for all flavors. That's not how any of this works.
There are good stats on ELR for each flavor - Personally I only use them as a guide, buty ou can usually get away with using the median mixing percentage :) Usually you can also read other people's notes on the flavor detail pages.
In fact, with ELR you don't need to look up the flavor any longer - as you add a flavor to your recipe, ELR will automatically suggest the median mixing percentage (which you can leave or just start typing your own) :)
http://forum.e-liquid-recipes.com/t/flavor-percentage-suggestions/216071
I don't know if this was it, but here's a spreadsheet involving that info (there are others that may be better, this is just the first one I found):
https://docs.google.com/spreadsheets/d/1agXdua8bEp8MV4z1mn3qX4AXCS4P0RxQXcy2lDa7ccc/pub?gid=0
I shoot for about 20% overall flavor.
I've found that usually about 15-20% total flavoring is adequate, and I divide the different flavors equally at first, and adjust from there; usually subtracting the overwhelming flavors first before I consider adding more of the others.
I max vg my recipes, aiming for 80vg/20PG, making calculations easier, but this depends a lot on the device; I only use rebuildables, for either dripping or squonking. For tanks with disposable coils, staying with the max 20% flavoring is a bit more complicated but still tastes about right; any more than that I either can't taste any difference, or its too much and ends up tasting like I just ate at an all you can eat buffet at the Yankee candle shop.
20% seems like a huge flavor load, and my whole mouth puckered so hard at reading your comment that I’m gonna need a speculum, K-Y jelly, and muscle relaxants to unfuck it.
Then again, maybe I’m the weird one. Most of my concentrates are FLV and a little goes a long way, and I’ve also got some OOO stuff in the garage that smells like cancer and death without even opening the bottles, so I can’t even imagine using any of them at a 20% total flavor load.
Probably is no optimal since once you combine with other flavors it changes. I havent used a recipe in years, I just know how much nicotine to add for 2-3mg, how much VG/PG to use by weight and how much total flavor I want as a % for whatever size bottle I'm mixing in... Then I just add in flavors until I hit that percent. Yet to make a bad mix... Some have been educational and know to dial what flavors back and which I can push etc.
2.5% is my go to for a start on almost everything but sweeteners and coolants. .5% on those 2