Format the letter the same as a standard business letter beginning with the header information using the standard military block format that lines everything up flush left on the page. Put your address at the top. Don't put your name, just your street address, city, state, and ZIP code. You will sign off with your name. Then leave a blank line and put the date you are writing the letter. Leave a blank line and put the address for your new command. Be sure to address the letter to your new commander and make sure you spell his name right. Skip another line and put in your salutation, followed by a colon.
Begin the body of the letter with one or two sentences about why you're writing, or the subject of your letter. This could be to introduce yourself, to let the new commander know of any changes to your itinerary, or to request an initial meeting with your commander. For example: "My flight from Korea has been changed and I will be arriving in CONUS, on Friday, July 30th at 10:00 a.m. I would like to schedule a meeting for that day, if possible. In the meantime, here's some more information about my background and skills. I look forward to my new company command.
Put in a blank line and continue the body of the letter with an additional paragraph or two elaborating on your subject line. Continuing with the example above, you would tell your new commander about your background and special skills. For example. you could write: "I have spent the last five years as a rifle platoon leader, the last two years with the 2nd Infantry Division in Korea. In that capacity, I was in charge of the quick reaction force. As you know, we had to be ready to deploy in a moment's notice in the event of a breach of security on the DMZ. I believe this position more than any other has given me the quick-thinking skills, and leadership experience necessary to be an effective company commander. I look forward to serving you and am preparing for my new position by reading the battalion history.
Skip a line and close the letter by making note of any attachments you're including in the letter. For example: "I have enclosed all of my Officer Evaluation Reports as well as my most recent APFT test results for your review." Skip another line and add a closing phrase, such as "regards," or "sincerely." Leave four blank lines between the closing and your typed signature. Between those lines sign your name.