The first thing to consider when embarking upon the creation of any image is the hierarchical flow of elements to be introduced, along with their relationship to the grander scheme of your compositional goals.
I knew from the start that I wanted to create a woodland landscape of some sort, so I devised a mental outline starting with the most prevalent and basic items to be blocked out followed by those of increasing number and/or complexity. Taking this small, simple yet important, step helps you to maintain a level-headed perspective during the creational process should any issues arise.
With that said, it is now time to move onto the initial phases of my modeling process. After opening up a new scene, I switched into the front camera view and assigned my loose concept image a couple of units beneath the grid using Maya's image plane feature.
Next, I created a poly primitive plane and positioned it over where the image had been placed. Using the Split Polygon tool and the reference as a guide, I began redirecting the edge flow of the vertices to loop where I intended to place the lakes of water or portal hubs on the land (Fig.02).
Once this was complete, I activated the Sculpt Polygon tool with Pull switched on to a moderate displace height. I then set about creating some interesting features of irregularity on the landscape, being careful not to disturb the border edges that were to be framed later on too greatly. Hitting B and mouse scroll left, I decreased by brush size and held Alt to inverse the brush direction to sculpt in the cavity areas drawn in earlier (Fig.03).