I think the TFA Butterscotch is quite nice. I mix it at 15% 70/30 (VG/PG) at 1.5 mg. I think I could even go up to like 17-18% and still be a nice balance! I haven't tried other Butterscotch's but TFA makes a good!
I like to test my flavors that I am unsure of what their overall flavor profile is. So I make small batches of single flavors to test them out and see how they will mix with other flavors. Not every manufacturer makes flavors taste the same, so each one is totally different. I find that when I don't try them out first the mix never turns out. I just made a Mango Watermelon using TFA, pretty standard simple recipe, mixed at 5% Watermelon and 15% Mango (previously used LorAnn's at same %'s) but it was all Perfume!! Was so gross and frustrating! Luckily only mixed a 3 ml batch. So I tried both the Mango and Watermelon and they are very light on flavor compared to LorAnn's, so I adjusted the %'s a little and it turned out much better! The watermelon from TFA seems to have a Parfumey note to it at Higher %'s, but also has a very light Watermelon flavor, so quite disappointed by this. I think I'll try Cappella next!