Waitrose also has a line called Perfectly Ripe so if you use Ocado for delivery, that's how you can be sure you're getting immediately edible ones! Mmmm. I LOVE avocados SO much!!!
I tend to make really, really simple guac. 'cause I like the taste of avocados so much. I mush up a couple of them, mix that with some salt, tabasco, and a squeeze of lime juice and then add a handful of halved cherry tomatoes and another chopped avocado to so it's a little chunky. Sometimes I add a bit of salsa but I absolutely hate coriander, and almost all salsas seem to have it.
As for soured cream, I use creme fraiche instead. It tastes REALLY similar but is much nicer, IMHO....