If your name is George W. Brown, do not write it at one time as here given, and again as G. Washington Brown, or G. W. Brown.
Adopt one form and stick to it.
If you are writing for a firm or for another as clerk or secretary, always sign the firm name, and below it your own name preceded by the word "per," meaning "by" or "through."
THE MATERIALS
Never use scraps of paper or soiled paper to write on if better can be had. The materials of a letter affect the receiver, particularly if a stranger, just as one is affected by the garb of a stranger before he speaks.
Use a good pen and black ink.
Fold your paper so that it will fit the envelope.
Avoid blots and erasures; they indicate carelessness or unbecoming haste.
Address your letter distinctly.
Here is a good form: