BBQ doesn't have to involve sauce. I am a die-hard BBQ lover and I always laughed at Texas BBQ.... until I lived there.
Sauce is a garnish. BBQ is a process.
I haven't won any trophies or ribbons, but I have won the hearts of many friends with my rub. I will offer this:
1- you need a salt. It creates an osmotic pressure difference which not only pulls water out of the meat, but pulls salt into it. The result is a curing that is a wonderful thing. I prefer Kosher salt. It is basically NaCl. No additives, no iodization, just salt. Sea Salt is great but unpredictable.
2- you need a pepper. This is not to be confused with a chile pepper, that is later. You should have a member of the Piper negrum family such as black pepper or one of its variants (green, white, red).
3- you need a chile pepper. This doesn't have to be spicy hot, but the flavor of peppers should be a part of it. Anaheim chiles are a good flavorful pepper that is low on the Scoville scale. Cayenne pepper is high on the scale while low on flavor. One of the reasons that Jalepenos are so popular is because they combine a good mix of both.
4- you need a hook. This is the spice that links the heat to the meat. They are savory spices that imply a link between the chiles and the other spices; cumin, paprika, turmeric, mustard, etc.
5- you need a sugar. That doesn't mean your rub needs to be sweet, but just like a good marinara sauce, it needs sugar to make the flavors pop. If you choose to add enough to make it sweet, go for it. Trust me on this step.... Don't use white sugar. It will burn at BBQ temps and leave a taste of burnt marshmallow. Brown sugar is your friend. Molasses works well, but it will no longer be a dry rub.
6- you need a blend of secret flavors. This is up to you. The above stuff is a baseline starting point. The actual spices you use to round it out are your choice. Rosemary, Sage, Thyme, Coriander, Dill, Fennel, Bay, Curry, Maple, Garlic, Anise, Cloves, Cinnamon, whatever.
A great secret I learned from a friend was to use low-heat chiles (like ground Anaheims) with a little dash of Wasabi powder. The Anaheim chiles have great flavor and the Wasabi adds a bit of up-front heat that doesn't fry your taste buds. For people who like the heat, they get the heat. For people like me who hate the tongue-blistering properties of spicy food, I get the heat but it goes away fast without destroying the experience.