Cut open the avocados, remove the pits and transfer the avocado flesh to a large mixing bowl. Use a citrus squeezer to juice 2 to 3 limes (for a total of ¼ cup or 4 tablespoons) into the bowl with the avocado.
If you have any additions, such as fresh cilantro, onions, jalapeno pepper or chili peppers, salsa, sour cream, or fresh tomatoes, stir them in until well combined.