Pat the thighs dry with a paper towel and brush on a little neutral oil and season on all sides. (Chicken can be prepped, seasoned and refrigerated uncovered for 3 to 24 hours before cooking for optimal flavor.)
Prep and preheat the grill to 450° F with a two-zone grilling setup (see note). Clean the grates with an oiled paper towel and tongs or grill brush.
Sear the thighs skin-side down for 3-5 minutes, keeping an eye on flare-ups.
Turn and cook for 3-5 more minutes, then transfer to the cooler side.
Continue to cook until the internal temperature reaches 175-185° F. About 25-35 minutes total for bone-in, depending on the thickness of the chicken and temperature of the grill.
Rest for 5 minutes before serving.
A two-zone grilling setup has one side of the grill with high, direct heat and the other side with lower, indirect heat.
If using a sauce like BBQ or Huli Huli, don't put any on until about 10 minutes before finished.
Be careful of sugary marinades and sauces, as they can easily char on direct heat/flame.