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!!!
I'm not big on gallery walls, but I like this idea. Make it a small smattering over a hall table/entryway bench, and fill in spaces with small items/letters instead of just a bunch of similarly-sized frames.