It also varies WILDLY from person to person; people still gape open-mouthed at the high percentages I use, which is immaterial to me -- i want to *taste* my vape, not just smell it. If someone tells you to use 2% or 4%, and you try 8% and it still tastes like barely-flavored water... then it's time to double it again to 16% to see if it actually CAN be tasted.
The best suggestion is that when you're mixing something for the first time and don't have any idea how much flavoring or in what ratio the various flavors should be (there really aren't any flavors that are perfect all by themselves), mix only about 6ml, to test -- if it's good, you can make more; if it's terrible or just can't taste it, you haven't wasted much. Most folks say 5ml, but even numbers of ml's are easier to deal with, when the quantity is that small -- you generally stay in the hundredths-of-ml's, rather than going another decimal place into thousandths. Rule of thumb: about 50%, main flavor; about 50%, supporting flavors (vanillas, creams, sweetener, other additives).
Andria
