Heat gas or charcoal grill. In small bowl, combine honey, soy sauce, red pepper flakes (if you use them) and garlic; blend well with wire whisk. Set aside. Brush chicken thighs with oil; sprinkle with salt and pepper.
When grill is heated, place chicken on gas grill over medium heat or on charcoal grill 4 to 6 inches from medium coals. Cook covered 8 to 12 minutes or until juice is clear when center of thickest part is cut (180°F), turning once and brushing with honey mixture during last 2 minutes of cooking time.