Originally posted by knighttemplar1960:

Because they respawn if you find a large clump of them it makes sense to put a pin on your minimap and label the pin so that you remember what respawns there. Then when you need more berries/mushrooms you can sprint from pin to pin.

Great tip. I usually mark spawns that have 4 or more. And then I pick a day here and there where I go out and gather shrooms, rasberries, blue berries and thorns all in a go.