Use multiple frames and objects to create a larger shape like a square or rectangle. Maybe start with edges and fill in toward the middle. Incorporate the refillable frames into this gallery? In bolder colors than the other pin.
why not entirely fill up a wall space with pictures?
mirrors on the wall http://vidaeartedesign.blogspot.com.br/2012_03_01_archive.html
GOMA Matisse exhibition cafe design--- The hanging lights are a constant theme
54 Reclaimed barn beam light fixture with 12 by 7MWoodworking
Vintage Industrial Pair of Gear Pendant Lights L K | eBay:
Industrial bar, exposed brick, dark wood, exposed vents, red lighting Trafiq Bar in Budapest