I know many of you have asked me how to do collages. I don't know that there is a "wrong" way because there are so many ways! Below are some examples... all same frame or just all same color, symmetrical, not symmetrical, only frames or throwing other objects or mirrors in with it! It's all up to you. I'm also going to show you the progression of the wall I did in my own house. A lot depends on the style of your house, how big the wall is and how much you want or need to display.
To install, there are also several ways, but I almost always sketch it, lay it out on the floor, measure what I need to, and take a picture after I get it just right. You can tape off the area that you want to stay within (using painters tape), then you will know that everything is square. You can measure between every frame and get it perfect, or, as I like to do, just start hanging and eye-ball it!
Let me know if you ever need help! They are sure fun, and a great way to fill a wall with all those pictures! Be Creative!