"I don't really follow an exact recipe, but here are the ingredients and general guidelines.
First - make Pico de Gallo
Tomatoes (I usually use roma tomatoes, but I think any would do), white onion, cilantro - sprinkle salt. Tomato is the primary ingredient here, add as much/little onion and cilantro as your taste buds like relative to tomatoes.
Second -
Avocado - about 50% of your total recipe should be avocado, so if I use 2 small tomatoes, I'd do 4 small avocados. If I use 2 large tomatoes, I'd use 4 large avocados - you get my drift. Cut them in half and spoon out the middle - don't chop up or mash.
Third - heat
The last time I made guac I used one whole serrano pepper that was about 5" long finely chopped up. If you want it hotter or cooler, add more or less serrano pepper.
Put your pico, avocado, and peppers into a glass bowl. sprinkle salt and freshly ground pepper over the top. Squeeze a fresh whole lime over the top as well - this tastes really good and helps preserve the avocado from turning brown. If you make a lot of guac, you may want more lime juice.
With a sharp knife, mix your guac by cutting through it. You want your avocado to get cut into little chunks, but there is no need to make it a paste. Once your avocado is cut enough, you can go to mixing with a spoon. Add salt and pepper until it tastes amazing. It usually does not take very much. :)
I think that is about it. :)
shopping list:
4 avocados
2 tomatoes
1 white onion
1 bunch cilantro
1-2 serrano peppers
1 lime
salt
pepper