Combine 2 tablespoons Kosher salt, 1 tablespoon freshly ground black pepper, 1 tablespoon garlic powder, 1 tablespoon onion powder, 1 tablespoon smoked paprika, and 1 teaspoon dried thyme in a small bowl. If using, add ½ teaspoon cayenne pepper.
Whisk all the spices together until evenly distributed.
Transfer the seasoning blend to an airtight container and store in a cool, dark place.
To use, pat your steak dry, then generously rub the seasoning over both sides. Let the steak rest at room temperature for 30 minutes before cooking.
Cook the steak to your desired doneness, then let it rest for 5–10 minutes before slicing and serving.