Trim excess hard fat and silver skin. Remove the membrane only if using back ribs.
Pat ribs dry and coat lightly with mustard if desired.
Mix salt, pepper, and garlic powder, then season all sides generously.
Refrigerate for 30–60 minutes.
Preheat smoker to 250°F (121°C).
Add post oak, hickory, or pecan wood.
Place ribs bone-side down.
Smoke until internal temperature reaches 165–170°F, about 5–6 hours.
Optional: wrap in pink butcher paper.
Continue smoking until internal temperature reaches 203°F and the probe slides in easily.
Rest for 30–45 minutes.
Slice and serve.