In a small bowl, combine chili powder, ground cumin, smoked paprika, garlic powder, onion powder, dried oregano, sea salt, black pepper, and cayenne pepper (if using).
Stir until all the ingredients are thoroughly mixed and evenly distributed.
Transfer the Southwestern seasoning blend into an airtight container.
Store the container in a cool, dry place, away from direct sunlight.
Use as desired to add Southwestern flair to your favorite dishes.