Groupings of mixed and matched art and frames, is a popular theme today. Unlike a matched set of art that is generally framed the same and hung in a highly structured way, random groups are usually framed to suit each individual piece and arranged more casually. Many people like to lay the pieces out on the floor to see the overall balance before committing to making holes in the wall.
Once you know how many frames you want to hang, you can also cut pieces of paper the size of each frame and tape to the wall to experience the final effect. Measure the distance from the center of the hanging wire to the top edge of the frame. Mark that measurement from the top at the center line of each frame tracing and mark that point on the wall with a PENCIL. Place your picture hangers at the marked point on the wall and hang your photos.