Breaking ground. The biggest mistake people make is to think the concrete comes first. This is true if a concrete slab is all you desire. If you are wanting more for your patio, think about adding footings for overhead structures, plumbing for water and gas, electrical runs for power to fans and lights. This can be a costly mistake if you're not thinking ahead.
Once you know what you will be doing with your outdoor patio, it will be easy to determine the appropriate size for it. Will you be using it for barbecue parties on weekends, or will you keep it as a peaceful retreat for yourself and your family? Share these priorities with your Sunset Contractor so that you both understand the final result of the patio construction that you are looking for.