A few months ago I hired Mike Sommer to design me a studio. I was thinking it would be a booth with a control room type of setup. Mike advised me to keep the microphone in a large space. I've read that the BBC recommends that a sound booth be no smaller than 1500 cubic feet. The room I had available was aprox 12x15x8 for a total cubic volume of 1440.. that will have to do.
Here's Mike's design for the space.
and here is how the space looked when I started. It was FILLED with junk as the room was a catch all for all sorts of projects.