Heat a skillet over medium heat.
Add the ground beef to the skillet and cook until browned.
Drain excess fat from the beef.
Add taco seasoning and a splash of water to the beef.
Stir well and let it simmer for 5 minutes.
Meanwhile, warm the corn tortillas in a separate pan.
Prepare the toppings: dice onions, chop cilantro, and dice tomatoes.
Assemble the tacos by placing beef on the warmed tortillas.
Add onions, cilantro, and tomatoes on top of the beef.
Serve with lime wedges and optional salsa or guacamole.