Painting techniques for flat layout?

Well, using a sponge makes a more realistic "fuzzy" bush or tree, yes, but most of the printed toy tableclothes and rubs, etc., I have seen don't have fuzzy bushes.  Everything is well delineated" it is obviously not realistic so I don't even think they go for that look as much as "neat."  so bushes are round and often have a thin black line around their edge, etc.  

I recommend an oil based paint, not necessarily glossy but not necessarily flat, either.  You might study some of the Brio/Learning Tree Thomas fold out train set boards so get ideas about how they do it: the look is good.

Garrett76,

You would create the effect with highlight lines of a lighter shade of color of the object.

I just did this tree in MS Paint with the spray tool. It's a little rough with a mouse, but I was thinking rattle can.

here's an artist creating 3D with a flat surface. A little different, because on the platform, the object would be a top view or at perhaps at a slight angle.

Another idea,

Look at satellite views in Google Maps to get the illusion. This clump of trees in Lutherville, MD looks like different sized sponges with a few colors would work.

Roads look flat. A slight tilt on structures and objects such as street lights and traffic lights with a thin line would look ok.

It's still about varying shades of color for the effect.

Hello Moonman

Great idea to study Google Maps.

I am going to try this process

Side bar item: My favorite tune of all times and all decades is "Blue Moon"

Your name made me think of this tune. 

Thanks for sharing.....