I fill a 3ml bottle with 20 drops of pg with dropper .The bottle is marked off for the 20 drop level. Then i add one drop of flavoring with the same dropper . I then shake the bottle and put 3 drops in a atty and vape it. I then add 2 drops pg and another drop flavoring to keep the bottle at the marked level . Next i drop 3 drops and vape (10%) . Then repeat until 20-25% just to be sure i dont undershoot my sweet spot and to know what it tastes like when it reaches a over flavored percentage . On flavors i think are going to be stronger i will start with a 40 drop base so i can start at 2.5% . Its not 100% accurate but its pretty close . I have done this on about 90 out of the 100+ flavorings i have .Its works really well to improve your diying . I dont know how id diy without doing it now . On each flavor i take notes and right down the sweet spot percentage and then taste notes on the flavor and overflavor etc . I also let them steep when im done and try it the next day and write notes on the taste after steeping . I have probably 90% of my Capellas flavoring to be right at 15% . Iv found 2 or 3 i think to be under 15% and a few that were 20% . My numbers do vary a lot with other vendors. HealthCabin is one that iv found almost all to be under 5% . Some like cereal sweetcorn was best at .75% . I had to dilute it in pg .[/QUOTE]