On a cutting board or plate, mash avocado with a fork (if you're making a lot, use a potato masher!). My favorite consistency is guacamole-like, but you can make it a more creamy texture or chunkier if you prefer.
Squeeze a teaspoon of lemon juice on to your avocado mash and gently incorporate.
Sprinkle with a pinch of salt and pepper to taste.