• The four most important typographic considerations for body text are point size, line spacing, line length, and font (see font recommendations), because those choices determine how the body text looks.
• Point size should be 10–12 points in printed documents, 15-25 pixels on the web.
• Line spacing should be 120–145% of the point size.
• The average line length should be 45–90 characters (including spaces).
• The easiest and most visible improvement you can make to your typography is to use a professional font, like those found in font recommendations.
• Use curly quotation marks, not straight ones (see straight and curly quotes).
• Use bold or italic as little as possible, and not together.
• Never underline, except perhaps for web links.
• All caps are fine for less than one line of text.
• Put only one space between sentences.
• Don’t use multiple word spaces or other white-space characters in a row.
• If you don’t have real small caps, don’t use them at all.
• Kerning should always be turned on.
• Use first-line indents that are one to four times the point size of the text, or use 4–10 points of space between paragraphs. Don’t use both.
• Always use hyphenation with justified text.
• Don’t confuse hyphens and dashes, and don’t use multiple hyphens as a dash.
• Use ampersands sparingly, unless included in a proper name.
• Use proper trademark and copyright symbols—not alphabetic approximations.
• In a document longer than three pages, one exclamation point is plenty (see question marks and exclamation points).
• Put a nonbreaking space after paragraph and section marks.