Some places sell all-in-one mixing kits (Totally Wicked is the first one that comes to mind, but they are not the cheapest and there are others out there)
Basically, all you need is:
Nicotine base
Diluents (PG, VG, etc)
Flavoring
There are plenty of sources of all of these. RTSvapes looks to me to be one of the cheapest ones for PG, VG and nic. Haven't ordered from them yet, myself, but I plan to when I next re-stock my supplies since I've heard good
reviews and their prices are good. There are a lot of vendors that carry flavorings, but I've only so far purchased from a few (TW, VaporRenu, DIYflavorshack). If you want a good coffee flavor, I highly recommend the Decadent Vapors Cafe Brisiliano and Doppio Espresso (sold by TW, though they won't be carrying them for much longer), my favorite coffee vapes. I can't recommend any particular tobacco flavors to try in your mixing adventures since I don't vape very many, myself
As for recipe, try a mixing calculator to get your quantities. You just punch in your ingredients and nic and flavor strength and it'll tell you how much of each to use. You may find these useful:
DIY E-Liquid (E-Juice) Mixing Station!
eJuice Recipe Calculator
I recommend starting with small quantities at first so that if a bad mix is made or you don't like a particular flavoring, then you haven't wasted much materials.
Above all, just have fun experimenting with mixing and don't sweat it if you make a bad batch, we all do ;-)