Basic Book Design/Me, Myself and I
Avoid mentioning yourself when writing. We naturally talk about ourselves in conversation, so it's easy to write this way. But it doesn't sound professional.
Use Find to search for "I" and "me". Rewrite the sentences without mentioning yourself. Or take out the material—it probably doesn't add anything.
Using the phrase "the author" sounds stuffy.
Avoid telling personal stories. Stories take up more room than simply stating the point.
Like unusual fonts, break this rule if you have a good reason. E.g., your book is a memoir, or a book of personal essays.