Peel and dice avocado, then add in lime juice and salt, then stir in chopped cilantro.
Add in any other additions you prefer.
Guacamole needs the acid of the lime to hold its color, the other thing that helps keep it bright green is to not expose it to air until served, so place plastic wrap directly on top of it in a container, then place a lid on top of the container.
If you know the guacamole is going to sit out longer than 1/2 hour add a little more lime juice so it doesn't brown.
*multiply for more servings