Be sure to align all edges of paper. Space your information proportionally. A good way is to divide your poster either horizontally or vertically into three or four sections, and place your materials within those sections. When choosing a background to frame the components of your poster, remember that neutral or grayish colors in your selection of poster or matte board will be easier on the eyes than a bright color. Dark backgrounds will make a dark photo seem brighter and vice versa.
Color photographs look best when mounted on a grayish backing.
Usually posters are put up with tacks on a corkboard. This can also make for a more visually attractive presentation, and is easier to setup.