Decide on what kind of footnote you want to write: a reference footnote, a content footnote, or a combination of the two. The last option is usually used if you have something specific to say about the source that you have just cited that you cannot fit into the body of your essay. A reference footnote will direct your reader to the source that you are citing (for example: 1. See Fitzpatrick 187-88.). A content footnote provides further explanation that would otherwise not fit in the body of your essay (for example: 2. In the same passage, Fitzpatrick goes on to note that "as long as there is life, memories are eternal" (189), thus cementing my point.") (Reference 2).
Open the "Insert" menu in your word processor, while your cursor is in the place where you want to place the number that will point to your footnote. On the "Insert" menu choose the "Footnote" (or "Reference" and then "Footnote") option. If you are writing by hand, write a superscript number in the place where you want to point your reader to your note and then write the same number at the bottom of the page to mark where the note will be.
Write your footnote beside the number at the bottom of the page. Make sure that this number appears at the point in the body of your essay at which you want to direct your reader to your footnote. For full information on writing a reference, content, or mixed footnote, see the link to the summary of a footnote's format and usage rules in your style guide in the References or Resources section of this article.
Check that your note is still necessary as you write and rewrite drafts of your essay or book. This is an important step because as you rewrite and edit your work you may find that you no longer need the reference contained in a footnote or that you are able to include a footnote's extra information in the body of your work. In either of these cases the footnote can be removed from your draft. If you are writing by hand, make sure to keep the location of your footnote consistent between drafts.