There are exactly the same number of BBQ sauce recipes here in Texas as there are BBQ cooks, which is around 15 million.

The first question would be, are you going to use it for basting, a table condiment or both? The basting sauces are usually quite different than those you would serve for brisket or sausage on the table.

Brown sugar is a common ingredient but remember that it will carmalize on the grill.
Apple Cider Vinegar is a common ingredient and a small amount will "wake up" the recipe.
Chipotle has that smokey flavor and I like to use a good chipotle sauce for the heat.
Garlic, onion, black pepper, salt, chile powder, cumin, tabasco, molasses, tomato sauce, Worcestershire sauce, paprika, mustard are all sometimes used. A pretty good "all around" sauce recipe is:

16 oz can tomato sauce
1/2 cup (4 oz) water
1/4 cup (2 oz) vinegar
2 tbs brown sugar
1/2 fresh onion - pureed, or 2 tbs onion powder
2-4 fresh garlic pods
or 1 tbs minced garlic-pureed,
or 1 tbs garlic powder
2 tbs Worcestershire sauce
1 tbs coarse black pepper

1 tbs Paprika
1 tsp Tobasco or Chipotle sauce
1 tsp chili powder
1 tsp dry mustard
1 tsp liquid smoke
1 tsp salt or cajun seasoning mix (homemade, Chachere's or Zatarain's)

Puree the fresh onion and garlic, if using fresh.
Add all ingredients to a thick walled pot.
Simmer for 30 minutes, stirring occasionally.
Add water or simmer longer to achieve the desired thickness; I do not like it too thick.
Makes a little over a pint , depending on how much you cook it down.
Keep refrigerated. The sauce is acid enough to store for several weeks in the refrigerator.