Preheat your grill or smoker to 300-325°F. While it comes up to temp, trim any excess fat from the ribs. Then, using a sharp, heavy knife, cut off the lower portion of the ribs—the strip of cartilage and small bones along the top edge. This section is known as the rib tips. If you're going for a more uniform, St. Louis-style rack, this step will square up the slab and help it cook more evenly.
Once that section has been removed, peel off the membrane from the bone side of the ribs, apply a thin coat of Worcestershire sauce as a binder, and season both sides generously with salt and pepper or your BBQ rub of choice. Once the smoker is preheated, add the ribs bone side down and smoke them untouched for 1 – 1 ½ hours. At this point, flip the ribs and cook for another hour.
Once each side begins to get a nice, charred exterior, flip the ribs back over so the meat side is facing upwards and begin to baste the ribs with the mop sauce (grab my recipe here), reapplying the sauce every 20 minutes or so. Allow the ribs to continue cooking until the skin has turned a deep mahogany color, the teeth begin to show, and the ribs have a nice bend to them when picked up (we call this passing the flop test). You can also look for an internal temperature of ~205 degrees. Once these cues occur, remove the ribs from the grill.
Apply the mop sauce one more time and wrap the ribs in aluminum foil. Allow them to rest for 30 minutes, then remove them from the wrap, slice them up, and serve. Enjoy!