Business Letter Writing. How to Write a Business Letter Handout. This technical writing handout is a handy guide on the six main parts of a business letter: heading, inside address, salutation, body, closing, signature. Includes a blank template, a reference sheet, two different formats, strategies handout, rubric and graphic organizer. You can print the reference sheet and the strategies handout front and back for student notebooks. Project or print out the format. Provide the rubric and gra