I started using beakers to mix, bought cheap ones on amazon. So much easier, I just rinse with hot water; worth every penny.Storage, Storage, Storage. So many flavorings. Since the op is just beginning, might I suggest to organize your flavorings now before it gets out of hand.
Also, store your nic safely away from kids, pets.
I mix by weight. I use Ketchup and Mustard squeeze bottles for my PG/VG.
I also like to use a mini funnel when mixing. No more aiming at that tiny opening.