Remove the backings and glass from all of your picture frames. Discard them or save them for other projects. You won’t need them for this project.
Wipe down each frame with an alcohol wipe to help the paint stick. This removes residue and dust that may make your paint chip later.
Spread out a drop cloth and place the frames on it. Spray paint all of the frames one color. This makes them look like part of a collection, no matter how different they are from each other. Pick a spray paint color that stands out against and complements your hallway décor. Soft creams always work well, while black and brown work with light walls. You may also choose a lighter or darker shade of the paint hue in your hallway.
Allow the frames to dry overnight and check the paint for evenness. Add another coat of paint, if necessary, and let that coat dry overnight as well.
Hold the frames up to your hallway wall, arranging and rearranging them until you find a pleasing configuration. Try mixing different sizes of the same shape or mingling circles and squares or ovals and rectangles.
Draw a little chalk dot on your wall along the top edge of each picture frame, marking where it goes. Tap a finishing nail into each chalk mark. Hang your picture frames, arranging them so they hang straight.