That is why this is under "organize". I came up with this solution using pictures in the 1/2 bath downstairs. We will display 1 picture from each trip we take that really captures where we were.
I could have built this a frame at a time but I was afraid it wouldn't look as intentional as I wanted it to.
After a few trips to the thrift store to collect all of the frames, I painted them all with the same spray paint.
Trace all of your frames on paper and mark where the nail should go with a dot on the paper. Label the paper and back of the frame so you know which frame goes with which paper.
Cut the traced frames out and tape the papers up on the wall until you get them where you want them. Pay attention to anything that may hit the frames like a doorknob.
Put a nail through the mark you made for the nail on the paper. Remove the paper and hang the frame.
Use a combination of black and white & colored photos for interest. Fill any picture-less frame with patterned paper or images. I used vintage suitcases in 50% transparency so they wouldn't draw too much attention away from the trip pictures.
(I have this thing against pictures of people in the bathroom- I feel like "someone's watching you"! But if their back is turned I am OK with it.)
On the other wall I hung this shadow box. We will fill it with small things we pick up when we travel. i.e. a shell or a little bottle of sand from the beach.