They should be presented as finished products, unless otherwise specified. This means they must have a thesis of some sort, and present reasoned arguments through the examination of evidence. There should be an introductory thesis statement and a conclusion. Paragraphs should be used as a way to structure the argument so a reader can follow your thinking. Please stick to plain old white paper and standard fonts.
Pictures are nice, but strictly optional.
Pictures cannot be a substitute for writing. Nice presentation is always welcome, but please be clear that adding pictures will not affect your grade unless they are explicitly part of the assignment. An interesting or informative title is necessary. A funny title is fine. Spelling and grammar are expected to be excruciatingly correct.