A good rub has three components: salt, sugar, and spices in a 3:2:2 ratio. Playing within this ratio will allow you to create a consistently well-seasoned product while changing the flavor profile to fit your taste. We also have found that brown sugar is the best choice for your rub, being that brown sugar is white sugar plus molasses. The molasses brings extra flavor and moisture while helping the sugar caramelize at a lower temperature on your BBQ, again helping to create that beautiful crust.
Our favorite spice blend is simple; paprika, chili powder, black pepper, granulated garlic, cumin, and onion powder. Personally, I like the addition of harissa and dry mustard, but they are completely optional.