I simply take a store brand sauce and mix in a bit of honey & BBQ rub. Sometimes I'll also add a bit of cider vinegar, when I'm in the mood for a little more twangy sauce.
I tried making my own sauce before. After spending about $20, I ended up with about a half gallon and didn't care for it very much. I've had some GREAT homemade sauces, but I'm one of those folks that prefers to take a sauce and doctor it up a bit.