Arvid Schneider has launched a new 5-part tutorial series on setting up, shading and lighting some nice-looking mushrooms.
Here is the first part about shading the hero mushrooms:
PART 2 will be about shading the other assets
PART 3 will focus on lighting
PART 4 will add additional details, like Xgen fur
PART 5 will be the final touches in compositing
You can find more details on the series here.