If you do decide to go full D.I.Y. and buy flavour concentrates I would urge you to go to a website called e-liquid-recipes.com where you can go to flavours, type in the flavour and manufacturer that you are thinking of buying, click on the one with the most recipes and read the notes section on what other mixers have to say about it. The best way to start D.I.Y. is to find a few recipes that you like the look of and that also have some good recent feedback reviews and then purchase the flavours to make it, only buy 10ml bottles of concentrates until you really know that you like that particular flavour and will be using it often. Mix only 10ml batches of recipes and don’t forget that many of these will need steeping with anything from a few days (normally fruits) up to a month or so for creams and custards.