DIY: Gallery Wall Arrangement Ideas - plus many other guides, such as yardage guides for upholstered furniture, window treatment & terminology guides, area rug size guides, etc. This is an excellent resource!!!
Spiral Gallery Wall Layout Tip: start with placing the center frame, and then spiral out the other frames in the arrangement you see. Make sure there is an even amount of space between all of the other frames and the center frame. The outer frames will lend to a natural square shape.