The following are some general remarks on essay style, some of which (or perhaps all of which) you'll already be familiar with:

  1. Always double space. But single space any quotation that's longer than 3 lines or so.
  2. Provide a covering sheet/title page.
  3. Number your pages (please!).
  4. Have a separate bibliography. Styles vary, but at a minimum the following information should be available for each item: author/title/place and date of publication. For an article, of course, you'll need to put in the journal title, volume, year and page numbers. Always alphabetize your entire bibliography by author!
  5. Usually, ancient authors do not form part of a formal bibliography (the assumption is that of course you have consulted them, and they should be part of the ongoing discussion in your paper). If you are going to include ancient authors in your bibliography, then put them under a separate heading. If you have had to refer in your essay to an author like Livy by the page number of a modern translation (in the event that the translation you used didn't provide the conventional book and chapter numbers), then you certainly must put it in the bibliography, so that your reader can consult the edition you used and find that particular passage.
  6. Citation styles vary. You can use footnotes (bottom of the page), endnotes (end of the essay), or citations enclosed in brackets within the text. If you choose the latter format, remember that it can only be used for brief references. For references to comparative material, or discussion of an opposing view, or anything that takes more space, you really need to use footnotes/endnotes.
  7. How many footnotes? Hard to say, since it varies from topic to topic, essay to essay, and expectations differ for a second-year paper and a fourth-year one. But at least one or two per page (as a rough breakdown for a total number) would be a good start. Certainly as few as three for a 10-page paper is not sufficient.
  8. Try to avoid using the traditional (and rather complex) footnoting shorthand of ibid., op.cit, loc. cit., and so on. It's a system that's used less and less these days, and one that's rarely used correctly in student essays. What has largely taken its place is the standard "author/short title" referencing system, reflected above (Citation of Secondary sources).
  9. Details. Don't (as in do not) use contractions. Learn the proper use of it's (= it is) and its (possessive). Avoid mixing present and past tenses. Shun the spurious historic present altogether: Alexander marches on Persepolis, where he sets fire to the great palace (as though it's being brought to you live by CNN). Make sure you put commas and apostrophes in the right place (examples to avoid: Augustus, was the first Roman emperor; Athen's).