Like QuiltE, when I designed my quilting studio, I broke out the graph paper also, and when I thought I had the layout the way I wanted it then I took painter's tape and taped the floor to mark out all the furniture placement and walls for shelving, peg board, design wall, etc., before I ever brought in the first piece of furniture or equipment.
I wandered around that (empty) room periodically for a number of days, making sure that I could maneuver comfortably around without hitting any of the "corners" that the tape represented, doors could open fully, supplies & tools would be close at hand, and that I liked the flow of the room. A few minor adjustments were made, and I am completely thrilled with my space.