So I had to try for myself. I used crumpled tissue paper, bark, dried mushrooms and fungus, a dollhouse window, a scrap of rodent wire, a couple of keys and the thing you stick the key into. Oh and a LOT of oak leaves big and small.
So I started sticking stuff on using matte gel medium. Then I gessoed over everything. Then I added more stuff because, well you can never have enough stuff. Then gessoed again. Then I decided to go over the leaves with light modeling paste to make them stick out more. Then I drew the veins in the leaves with a bamboo skewer. Then more gesso.
Then I decided it needed an eye peeping out of the leaves. So I did the paper clay thing again and after it dried,gel'd it on and added more leaves. Then gesso again. Now it is ready for painting.
The hardest part is to think monochromatically. Because it doesn't matter what color the things are 'cause they will all be gessoed and painted. The drying time is hard too. Patience is not my strongest virtue. And there is a LOT of drying in between layers and what not.
So as you can see the first layer of paint is burnt sienna. I have to get some more colors, but I am leaning towards reds and red-oranges and coppers and golds. Maybe a green, I don't know.
So check out her work, you will be inspired too.