For a simple rib rub, I make enough to put in a container and save, here is the basic one for me that never lets me down.
First mix 2 cups of brown sugar with equal parts (about 4 table spoons) of Paprika, Black Pepper, Cayenne pepper, Chili powder.
Then add about 2 spoons of garlic powder, onion powder, salt. Mix it all together and rub your ribs down and let them sit 1 hour up to overnight, depending on how rich you want the flavor. While smoking every hour I squirt apple cider vinegar and Dr Pepper on them to get a nice color. When the bone starts to protrude 1/4 of an inch, or the length of your fingernail wrap in foil and let them cook one more hour, then take them off the heat and let them sit for 30 minutes. Go easy on the pepper seasonings if you don't want them too spicy, I like sweet and spicy so I load up on the peppers. Hope this helps, it's my favorite go to rub, and if you take the brown sugar out, and add ground mustard seed it makes an excellent brisket rub too.