2 - 3 ripe avocados
finely chopped onion
2 - 3 tbsp lime juice
crème fraîche
black pepper

Halve the avocados, scoop out the flesh and mash it with a fork to a suitable consistency, or puree it using a blender/immersion blender. Add lime juice and finely chopped onion to taste. Add some crème fraîche to make the guacamole creamy. Season with pepper.

If the avocados are a bit past their prime and have stringy flesh which would give the guacamole an unpleasant consistency, the best thing besides avoiding this type of fruit is to puree the flesh using a blender/immersion blender or rub it through a sieve.
However, if you do not like your guacamole processed into baby food consistency, you might try cutting the flesh densely crosswise inside the avocado halves before scooping it out, to shorten the tough fibres.

Serving suggestion:
Serve guacamole as a part of tortilla dinner.

Recipe source: family recipe.