How to pick a ripe avocado perfect for guacamole: The avocado should fit in the palm of your hand and be slightly soft to touch. You could also pull the stem off the top and if it is a bright green, the avocado is still ripe. If you know you are making guacamole in a few days, you can buy a not-so-ripe, firmer avocado. Place the avocado in a brown paper bag with an apple, tomato or banana. The apple, tomato or banana produces ethylene gas which helps ripen the avocado.
1 small red onion, diced
1-2 cloves of garlic, minced
1 lemon, cut in half (save to squeeze for juice). Cut the other half into thin slices
garlic salt, to taste
pepper, to taste
Cut the avocados in half, remove pits. Slice lengthwise and then cross cut, scoop flesh from the skin. Mash with a potato masher or fork. Mix in onion, garlic, lemon juice, garlic salt and pepper. Cover guacamole with the thin slices of lemon until you are ready to serve, and to cover any leftovers (if there are any) to help prevent the avocados from browning.