Strive to be exact and specific, avoiding vagueness, ambiguity, and platitudes. If there are industry_ or field_specific concepts or terminology that are relevant to the task at hand, use them in a manner that will convey your competence and experience. Avoid any language that your audience may not understand. Your finished piece of writing should indicate how you meet the requirements you’ve listed and answer any questions raised in the description or prompt.
While a simple "Hi," "Hello," or even "Hey" is appropriate in casual correspondence, a more formal salutation is appropriate when you are emailing about a business_related matter, such as a cover letter, letter of recommendation, or inquiry letter.