Write a brief introduction to your photo essay. If the subject of your essay is "War in the Middle East," write briefly in your introduction about the particulars of the topic. Describe the conditions under which you took your photographs and what type of equipment you used. The Introduction should be between 100 and 150 words. Save most of the actual storytelling for the photographs.
Arrange your photographs in the order necessary to tell your story. Since many photo essays are journalistic in nature, the images should be arranged in logical story order, just like a written essay. This doesn't mean you can't do an abstract photo essay, but then you'll be creating a photo essay for the joy of viewing, not for telling a story. For the purpose of a photographic essay, the story you put together with your photos should stand on its own, before you add any text. This means you should aim for images that truly do speak a thousand words.
Write commentary for each image that adds something to the photograph. Don't just describe what the image shows. Your description may be in the form of a set up for the photograph, including the what, where and when of the picture. Include an anecdote that tells how you came about capturing the image. Be sure to point out details in the photo that may not be immediately evident to viewers.
Arrange photographs for effect. Placing one picture per page can be boring and makes every image seem to bear the same weight in the essay. Consider arranging several smaller photos together as a build up, then placing one larger image on a page of its own for a dramatic emphasis. Include a range of photos that both offer exposition and emotional content. The wider your range of pictures, the greater the impact of the story you want to tell.