I don't endorse any rules-of-thumb for foraging, but a much better differentiator for beginners is whether the mushroom has pores vs. gills under the cap. There are virtually no deadly varieties that have pores.
Never heard this one before. Adding it to my bug out notes. Thanks!
Put a few common pored edibles (Laetiporus sp., Cantharellus sp., Grifola frondosa, etc.) in your notes for sure though, with basic descriptions, as even their few remote lookalikes (at least pored ones -- some people think Omphalotus sp. look like Cantharellus for some reason) are just going to give you a moderate stomach upset at worst, and may be edible themselves.
Chantarelles don't have pores?
Everything else a good book for identification. If its not 100% clear that it is editable, it gets thrown away.
The other thing is that the truly deadly varieties, such as the subject of this article - Amanita phalloides, are really not that hard to avoid. When you're a novice forager, there are plenty of varieties that don't look remotely like Amanita, and are much easier to differentiate.
There are some hardcore foragers who even consume certain varieties of Amanita (some of which are edible!), but to me this would be too much of a hassle, since it would involve spore prints and maybe even microscopy of the spores to be absolutely sure.