I love the look of grouping lots of pictures of different sizes along a wall. What I do not love is trying to hang them by trial and error, leaving a trail of nail holes along the way.
A quick and easy way to avoid this problem is to create picture templates out of paper. Then using painter’s tape to adhere to the wall, create a mock-up of the display. When you’ve perfected the arrangement, you can even measure where the hanging mechanism falls on the back of the frame and then hammer the nail directly into the paper template. Then just tear away the paper and hang the photo/artwork.
Isn’t that easy? And think of all of the extra nail holes, fussing, and swearing that you saved.