If you are using the indented form, place your address at the top, with the left edge of the address aligned with the center of the page.
Politely request an interview at the employer’s convenience.
Indicate what supplementary material is being sent under separate cover and offer to provide additional information (a portfolio, a writing sample, a sample publication, a dossier, an audition tape), and explain how it can be obtained.
Precisely because this letter is your introduction to an employer and because first impressions count, you should take great care to write an impressive and effective letter.
Remember that the letter not only tells of your accomplishments but also reveals how effectively you can communicate.