I agree with what John said above and would concur that deciding how your want to interact with the layout is the most important consideration up front. I would also suggest spending time looking at other peoples layout to get inspiration, look at all kinds of layouts across scales to see what you like and to see what doesn't appeal to you, youtube is a great resource. Another suggest would be to not be afraid to build in stages. If you have a recent MTH catalog, they have a example of starting smaller, then adding additional sections at a later time.
Have fun!
