Correctamundo. Get a small syringe for those recipes that might be 1% of some flavor and a larger syringe for your nic/vg/pg. As long as you can do simple math (and I know you can), that is all you need for mixing. For example, if you are trying to fill a 60 mL bottle and your recipe calls for 10% X and 5% Y, then very simply, that is 6 mL of X and 3 mL of Y. Given that almost all flavors use PG as the carrier, subtract that amount out from the total PG you want, such as: 50/50 VG/PG mix (if you so desire) would be flavors plus 30 mL PG minus the flavors (in this case,30-9= 21 mL PG) + 30 mL VG... oh, and the nic, depending on what you buy and from whom, might be VG or PG, so figure that in as well. You do not need any fancy equipment to do this. And if you are off by a mL or so, it really doesn't matter that much because how you make it depends entirely on YOUR taste, not some friggin' chemist somewhere. And if Phil still doesn't like the idea, you do it for you and let him keep paying for his pina colada until one day he wakes up and notices that you are making some good shit and he is the one missing out.