Moonflame is correct. Distilled water or a high proof alcohol is normally only used to thin out VG. Many people (myself too) will purchase a higher nicotine product like 24 or 36mg strength and then cut it to reduce the nicotine strength and in the process end up reducing the flavor by approximately the same amount.
Let's say for example that I purchased a
20ml bottle of
24mg English Toffee. I wanted to cut it in half to end up with 12mg and I needed to make a 10ml batch. Without needing to use Dans calculator because this one is rather easy, I would put 5ml of English Toffee in a container, then I would need to add either 5ml of PG or VG or a combination of the two. I'm sensitive to PG so I would want to add 5ml of VG, but I have to thin it out because it is too thick. I would add 4.5ml of VG and .5ml of distilled water or alcohol to the mix. I've found that 10% (distilled water or alcohol) is about right to thin out my VG.
What I end up with is 5ml of English Toffee, and 5ml of thinned VG for a total of 10ml of a weak-flavored English Toffee mix at 12mg strength of nicotine. I would then add probably 3 drops of Loranns English Toffee flavoring to the mix, shake well and direct drip on my 510 atty to give it a try. This I would vape as it is for a half hour or so to make sure I'm getting the mix I made out of my 510. If I think the flavor was still too weak, I would add more drops of Loranns and try it again for a while. Be sure to keep track of the total number of Loranns you've added to the mix. Once I've gotten the flavor just right, I make a note of my recipe and I'll be able to make my next batch quickly.
Hope this helps.