Stir together white sugar, brown sugar, paprika, black pepper, garlic powder, salt, chili powder, and cayenne pepper until blended. Store in an airtight container until ready to use.
To use the rub, remove the membrane on the back of the ribs, and rub both sides of the ribs with the mixture. Don't skimp on the rub! Wrap the ribs with plastic, and refrigerate overnight. Cook the ribs slowly over indirect heat for 2 hours, basting with your favorite barbeque sauce during the last 20 minutes.
