Here's how I make mine:
1. Brown a pkg of ground beef in a heavy bottomed pot and once browned, add about 1/2 cup of chopped onion and 1/2 cup chopped green pepper and a couple of minced garlic cloves. Let the beef caramelize a little while the veggies soften.
2. Add 3/4 cup of ketchup, 1-2 tbsp tomato paste, 1/2 cup water, 1 tbsp of brown sugar, 1 tsp of chill powder, 1/2 tsp of dry mustard, 1/2 tsp of salt, 1/2 tsp of red pepper flakes and 1 tbsp of worcestershire.
3. Let it all simmer until the sauce is thick and serve on crusty buns!