Hi Noby,
Welcome to Permies. I would love to help you, but your question at this point is too nebulous to really allow good guidance. The
land, your location, materials at hand, clay type, your skill sets, and the list goes on. I would recommend going back through and reading all you can that is on this sight about Cobb, and anything else you can find. Then do a design that fits you land and location. From that point, we can give you help on the particulars of you
project. I feel bad that I haven't answered you more directly, but I believe I given you the best advice at this stage in your project. Let me know if you think I could have done better.
Regards,
jay