Hi richi dont if this will help, as i dont know how you want your final piece done, but in my opinion add a source of lighting it gives more depth and and a sense of 3d check that out:http://images2.layoutsparks.com/1/224121/dark-forest-night-image.jpg
Cheers ruben, thats a better pic of what im going for. The other one i had was in a previous post, but id say thats more on the mark.
what is cool with mushrooms, as you can see in your reference pictures, is their curvy shape, which is a good thing to play with when doing the composition...
I found a cool website about the shapes in different mushroomshttp://www.bukisa.com/articles/39801_fantastic-and-unique-shapes-of-mushrooms