books with photos, very in-depth descriptions, pictures and descriptions sent to friends who also forage, and when all else fails, spore samples.
I've only had to make it to spore samples 6-7 times because I couldn't identify with the first three methods. I will note that I never ate any of the ones I took spore samples of - because I was then able to correctly identify them as poisonous (or close enough that I wasn't willing to take the chance).
When you get to know the specific bits of anatomy of the mushroom body, the trees with which they're symbiotic, the seasons in which they occur, etc., then identifying different varieties becomes as clear as identifying a baseball vs. a tennis ball.
E.g: https://en.wikipedia.org/wiki/Volvopluteus_gloiocephalus#Edi... == In the United States, there have been several cases of Asian immigrants collecting and eating death caps (Amanita phalloides), under the mistaken assumption that they were Volvariella. ==
That has also happened here in Denmark.
When you put your fingers on the foot of a bolet, you know immediately, just from the firmness, relative temperature, etc.
It's magical.