In a skillet over medium heat, cook the ground beef until browned, about 5-7 minutes.

Drain excess fat, then add chili powder, cumin, garlic powder, and onion powder. Stir to combine and cook for an additional 2-3 minutes.

Warm the taco shells according to package instructions.

Fill each taco shell with the beef mixture, then top with shredded lettuce, diced tomatoes, shredded cheese, and sour cream.