I am Glad to be able to help Kroan.
The problem I see in your lighting in the mushroom is that it is gradually radiating in circles.
I interpret that it means that the light source is a small point in space really close to the object.
If you are representing sunlight it comes as straight rays directly from the sun. Imagine you have a giant plane emmiting light from every inch of its surface from far away.
That said, the sun makes hard shadows if the day has no clouds.(Due to the way light behaves.)
Remember, light always travels in straight lines.
So, I guess your main problem is choosing a lightsource and sticking with it.
Don’t be afraid of using big shapes of color and always follow the geometry of your forms.
You seem to be missing what a teacher of mine once called “Depth Opportunities”.
Whenever you can suggest volume do it! It will make your shapes more readable.
How does that translates to drawing?
For example(There are infinite more examples):
Make sure when one thing is overlaping another there is space to its suggested mass.
If it feels like a 3D game clipping you lost depth.
Also, I’ve give a bit more of space between the mushrooms’s features. Information needs breathing space.
I’ve also removed the inner outlines, I personally feel that the “outlines” work better on the outside but this is not a rule. There are artists that use internal lines with the same weight of the outlines. I just happen to think it is a bit distracting and color changes can do the same work.
Zanorin also gave a very valuable tip that I think it is fundamental:
If you can’t find an exact reference find something similar. That saved my hide many times now since it is almost impossible for an artist to know the bahavior of every single material by heart.
Here’s my take on the Mushroom House you posted yesterday I started editing it before you posted your new version:

I’ve cheated a little bit in the lighting but I did not have the time to find a better solution.
Hope it helps you a bit.