TFA chocolates have worked just fine with me, but not alone. Adding vanilla and sweetener has consistently gotten me to every chocolate I've reached for. Chocolate or Cacoa is generally a very bitter powder that does not taste very good on its own. However, add butter and vanilla and "sugar" and dairy and eggs and you can end up with one of the best flavors in the world. Works same way with juice flavors. I have not found any single flavor mixes that I like with TFA, but I have dozens of ADV recipes, and do wholesale private label juices to local vendors by the hundreds of bottles every month. For me, it's all about mixes, flavoring to taste, finding flavors to copy, and then enjoying the effort it takes to copy them, searching out other recipes in this forum, but also on many other forums, and making juices in very small batches (drops), then tweaking them over and over again until they work...for me. I have found that others share my taste, so it has worked well. The only problems I ever had was when I tried to make a vanilla custard and tried to use Capella flavors, and I could never get there, after three months of trying. I eventually switched back to TFA, and it's better than ever.
I enjoy mixing juices, and, over time, have learned a lot, and made a lot of good flavors, that everyone else seems to like. If I didn't vape and didn't enjoy mixing, I wouldn't do this DIY thing for anything. It can be expensive, time consuming, frustrating, and I would have given up had I not made about a $500 investment upfront in DIY. So, stayed with it, and after 6 months I got my first ADV. Many have followed, but I have literally hundreds, of flavorings that didn't work, and if one counts tweaking recipes, certainly thousands of recipes that have not worked. Patience is a must for this type of thing. However, once you do begin to understand the combinations, the juice improves dramatically, and anyone can learn to make great juice. On the complex recipes, try finding good recipes and following them. Then tweak them to taste. That is the only way you're going to find out how to do this yourself, imho. Tweaking is just training. It's the experimenting, and how you learn how the blends fit together. I often struggle with a single percentage of two different ingredients trying to find the sweet spot. You know you are really close, and by staying with it, you can close the gap and get the flavor YOU LIKE. If other people like my juice....great. The important thing is that I like it. I made it for my vaping pleasure, and added to what I liked for my family and friends' pleasure. I never had any commercial interests, and still don't, but, then again, I'm not going to ignore 300% wholesale markups, and hourly support of my family members. I already have three jobs. I don't need a vaping job. But if others like it, so be it. Keepin' it real, and just sharing my experiences. I only know what I've done, and certainly am no expert at any of this. Two cents.