It’s somewhat regional but everyone has his or her own favorite. Up North East they like a close to pure vinegar version of an ultra thin sauce. I’ve even seen it clear (although usually using cider vinegar).
South Carolina has it’s hands in different styles… but their claim to fame (thanks to Maurice Bessinger and family) is a tangy sweet mustard based sauce.
In the Piedmont area… or out West it’s also vinegar. But there’s a good squirt of tomato or ketchup in the mix.
We’ll cover all of them here… but first
Here’s a Barbecue Tricks version of a Western Carolina Vinegar sauce. Tart, hot and a bit sweet but thin enough to mix quietly into a pile of pulled pork without getting in the way of the smoke in the meat.