How to arrange picture wall before hanging

Trace around each frame on paper and cut it out to that size. Give each paper frame a number and give corresponding real frame the same number. Tape them to the wall and arrange/rearrange until you are happy with the result.

Oh, dear I lost my answer. To start again. While what Kathy suggest sounds logical in reality it isn't (or shouldn't be) the size of the frame that soley determines the placement of the picture. It is the picture itself that should determine that. In this grouping all the women are looking to their left. Things like this should be considered. The staircase art is always evolving, so I rehang things. Here I am not concerned with the direction of the women's gaze, but rather with the "fitting in" of the pictures, no need to rearrange all, only those that need to be. In some groupings the frame is the same size so then more than usual, it is the picture itself and its own orientation that you must consider.

Use paper to trace around each picture then cut to size. You can put a small piece of two sided tape on the back of each paper in order to hang and move them around until you find an arrangement you like. Then replace each piece of paper one at a time with your actual pictures.