Development of shape artwork.

I have started off by doing so initial thumbnail sketches. I am trying to create patterns out of the tunnel idea that could exist within the image. I am trying to keep the patterns simple and geometric. The geometric patterns I think will be easier to create vectors out of but, I ideally I would like the patterns complicated but the shapes used within them simple.

I need to get a better idea of the scale and also the how that pattern will work in the space given. I really need to make sure I stick to the size and dimensions given.