1. Gallery walls work best when there is a connecting element and a bit of repetition. You can link items together visually by using similar subjects, colour and frame style or size.
2. Structured or symmetrical groupings can be easier to design and add more of a formal feeling. If you decide to go for a structured look you would typically use the same style and size of frames, with consistent spacing between items.
3. My favourite type of gallery wall is one that is organic with a mix of media and sizes. I like to use colour of subject and frames to create a cohesive look. Mixing in different shapes, like adding a round mirror or a plate or branch helps to break up linear lines of frames and keeps things from becoming too similar.
4. A level is your best friend. I usually create level lines to divide the space I am working into cross sections. This really helps you to line up the tops, sides or bottoms of frames at the same height across the space, creating a balanced shape. Make templates of each piece by tracing on paper and tape your layout to the wall first. I normally start out with the largest piece because your eye will naturally be drawn to that point, then build above and below it.
5. Overlapping horizontally and vertically gives you spaces in between to group smaller items that can visually equal a larger frame.
6. My own gallery wall at home started out as a smaller grouping but has since grown to take over the entire wall. It is like interactive art, I am always staring at it, adding to it, I never get tired of it.
Just remember to have fun. You can create a gallery wall on any budget and it is a great place to showcase your personality through a multitude of interesting memorabilia.