Hiya folks! I've been around this forum a long time, but I don't post a lot, just occasionally when I see something I want to respond to.
I've read the previous five pages, and some of the earlier ones in this thread. I want to thank you, collectively, for nudging me to try the Hangsen flavors from ECX. I only use tobacco-ish flavors. I really enjoy the T5, Turkish, RY1, RY3, and Deluxe Tobacco. The DT is one that you don't want to make very strong, as it takes on a somewhat yucky flavor. I mixed a batch at 3%, which is my standard "one drop per milliliter" for most flavors, and I had to dilute it to about half that, and then it was GREAT, in my opinion. The RY1 and RY3 both seem a little bit flavorless, and adding a little more flavoring might make them have a stronger taste, but I tend to think of them as a nice mellow light cigarette taste at 3%. I often think they'd be a good base for experimenting with adding one or two drops of some other flavorings to enhance them, as they are pretty neutral, yet very pleasantly tasty if your taste buds aren't numbed by over-flavoring. T5 may be my favorite of these, but I think it's very similar to the RY1 and RY3 in being a fairly neutral light tobacco flavor, like most filter cigarettes tend to be. The Turkish has grown on me a lot lately, and I always look forward to it when its turn comes up in rotation. It's got a nice stronger tobacco-ish flavor.
I use the term "tobacco-ish" because, as you surely know, nobody has really captured the essence of a cigarette in the vaping flavorings, although a few come close to tasting like tobacco in some form. I think the main reason is that it's like the difference between bread and toast. If you're a toast lover, even the best bread in the world won't satisfy your craving for toast, because the toasting changes the nature of bread. It gives it an aromatic quality and that lovely burnt taste. It's the same with tobacco flavors. Tobacco has a great aromatic nature, both in the pouch and in the smoke, but they are totally different. What's missing is, frankly, the smoky flavor.
As for the one drop per milliliter issue, I tested many different flavorings from the most common flavor vendors. I tried several different droppers, and the drip tip bottles used by most vaping juice vendors. Keep in mind that most flavorings are in a PG base, so they are not thin like alcohol, and they don't have the same molecular tension of water. The standard of "20 drops per milliliter" is a laboratory standard of water in the standardized droppers they use. In the vaping world, I consistently found that most flavorings produced an "average" of 30 drops per milliliter. Some ran in the mid to high 20s, others in the low to mid 30s, but most were between 28 and 32 drops, if not right at 30. Your mileage may vary, depending on the types of droppers and the brands of flavorings, but I almost always stick to the 30 drops per milliliter standard in my mixing. But here's what's really important!! If you use the same type of dropper all the time and most of your flavorings are of similar viscosity, use the standards you like without fretting over whether it's a 3% or 5% mix. If 1 drop per milliliter tastes good to you, start with that, then adjust accordingly. When you read that someone is using 7% instead of 5%, don't fret about minor variations. You have to "grade on the curve." Set your own standards and assume the averages, and you should find that a difference of 2% probably means a drop or two in a 10 milliliter bottle. Experiment in minor changes, and you'll find your groove.
If you prefer to make scientific measurements in flavoring, get some measuring tools appropriate for fractions of milliliters. Count how many drops you use to fill exactly one milliliter by doing it at least ten times, counting each time then taking the average as your standard.
The link in my signature is to a free Excel spreadsheet I created that allows you to measure out vaping juices very exactly, or to take your averages and make adjustments to the drop-counts of each flavoring. Check it out. Download it and play with it. If it helps you, I'm glad. If not, no harm done. But it is kind of fun, as spreadsheets go. It has some cool buttons and macros that make it easy to navigate and create flavor mixes, then save them in a Word document as images of recipe cards. It's meant to be both fun and scientifically accurate. I think it succeeds, and I hope you'll agree.
Cheers!