In school poster projects, presentation and creativity often count every bit as much as content. Coming up with a novel layout or unusual presentation can sometimes wow a jaded teacher used to seeing the same basic poster ideas over and over. It will also make the project more enjoyable by allowing you to get really inventive instead of just following directions.
Make a history poster about an event as if you were actually there. Use historical posters, handmade sketches or even homemade "artefacts" as exhibits and write one or more short, first-person pieces describing how they fit into the event from the perspective of one of the participants. For example, if you are doing a report on the Lewis and Clark expedition and you live in an area they travelled through, you could include a leaf from a local plant and a description of how you (Meriwether Lewis or some other participant) found it and what use you think the plant might have to future travellers.
Cut out magazine clippings to create a literary collage. Find people who look like the principle characters and various objects to help act out the story. Your collage can depict a single important scene or tell the whole plot. Beneath the collage, include a brief description of the events you are depicting and their importance in the story.
Rather than creating a single large poster or a trifold, divide your school project into small parts and create a poster gallery. Each frame of the poster should be about 1 foot on each side and illustrate one small part of your project. For example, if you are doing a report about the branches of American government, make one poster about the legislative branch, one about the executive and one about the judicial. When you are done, display your posters in a row along a wall so that people can peruse them like a miniature museum exhibit.