[cc81]

I guess. But for many you learned from your parents or someone who knows and you usually pick a small subset that you are sure of

If you look at a page with our most poisonous mushrooms in Sweden: http://svampguiden.com/giftsvampar/lista/

and compare it with edible ones: http://svampguiden.com/matsvampar/lista/

As someone who rarely picks I would never pick a white mushroom for example because it is high risk even there are edible variants. However I'm sure when it comes to chanterelles and penny buns for example and those (+ one or two more) are plenty for me.