Crush garlic using a garlic press and place in mixing bowl with the onion.
Add lime juice, cilantro, and salt to bowl.
Cut avocado in half, remove pit, and scoop out flesh. Add to bowl and mash with a fork. Guacamole should have some lumps left; it should not be perfectly smooth.
Add more lime juice to taste if desired.Serve immediately.
Notes
Be sure to use very ripe avocados for the best tasting guacamole.