One way to create a wall collage is with framed photographs. Once you choose the perfect space, hang the photographs close together in any pattern you choose. Typically, you want to choose similar frames so that the collage has cohesiveness. Hang the pictures carefully, making sure each one is level and in the correct spot before adding the next one to the collage.
Before you hang the pictures, plan the collage out. You can do this by arranging it on a floor to make sure it looks the way you want it. You can play around with different combinations this way.
Another method is to put the pictures, magazine pages or posters directly on the wall overlapping each other. To do this, use a wall-safe adhesive so you do not rip the paint or wallpaper when you remove the collage. You may also choose to hang up cork board first, and pin the pictures directly to that. This is a great method if you want to rearrange your collage without any hassle. A wall collage looks better on a large, open space, so try to choose a wall that is best suited to show off your work, rather than a hallway or in a corner.