No philosophy, my systems morph over time...just like me. I think of audio systems in much the same way, as I think of music...it's all good at some time or another.
I guess if I were setting up an audio system for someone else (from scratch)...I would want to know about that persons listening habits, I would want to look at, and discuss the room, and any setup issues I think we may run into.
Components...I would start with speaker choices (hundreds of choices here...depending?). So, I guess I'll 3rd the “Aball Method” for setting up a system from scratch.
Dave