Go to spicebarn.com. You can find that special ingrediant to make your rub just right. I have an allpurpose rub that I liked alot. Then found beer extract powder, added a touch of that and now it is what I aways wanted it to be. I don't buy premade rubs. I go to my spice cuboard and just mix and taste. I do sometimes take a rub from a book and tweek it. I like sweet with ribs and sometimes heat, so I have 4 differnt rubs just for ribs. I like a savory flavor with beef. So I have 3 rubs for beef. Chicken is so universal that I use just about any of the 16 or so rubs I have on hand, that I made.
I hope this helps.