Business Letter Writing Guidelines. Here are guidelines for writing a business letter, so all your correspondence makes the best impression. Margins: Business letter margins should be about 1" all around. This gives your professional letter an uncluttered look. You should align your text to the left; this is how most documents are aligned, so it will make your letter readable. Letter Spacing: Leaving space in your letter creates a clear, uncluttered and easy to read look that the reader will appreciate. Your letter should be in block format: the entire letter should be aligned to the left and single_spaced except for a double space between paragraphs.
Guidelines for Names and Titles: The salutation should typically use the person's last name, along with a "Mr." or "Ms." In general, avoid using "Mrs." or "Miss" unless you are certain of how the woman wants to be addressed. When in doubt, default to using "Ms."