Missing a green thumb

So I’ve been trying to create a park and I’m stuck. I wanted to create some paths in the park so I tried using a boolean modifier to create it inside another mesh and so far it failed. I looked at the one from Blender Cookie and it still didn’t look right when I tried it. So I have no clue how to make it work.

Start by modelling paths, then fill faces for the rest. Or subdivide plane and use K in edit mode to cut path lines. Boolean tends to complicate living ;). Avoid if possible.
Happy blending!