I began a pin board for ideas I found that I especially liked. Here are some of my favorite ideas.
This is a neat way to display studio portraits. The wood hangers would probably not damage the photo, but other hangers could easily create indentations, so be careful of using clips. You can find the listing for this hanger here.
This is a great way to be able to easily change images your displaying. I like the idea that the color of the shutter can really enhance your space and the images.
I love the display here from Country Living Magazine. The brown with that bold blue wall looks great. Putting lots of like images together make a great large impact.
Some vintage frames, painted and strung with ribbon can be a good way to display your collection of old photos. I would use mini-clothespins, which would probably be the least harsh on the photos. Image is from Birch and Bird blog.
If you want to follow to see more you can see what I have so far on my Pinterest Board - Vintage Postcards and Photo Displays