Personal pronouns (like I, we, and you) are important in letters and memos. In such documents, it is perfectly appropriate to refer to yourself as I and to the reader as you. Be careful, however, when you use the pronoun we in a business letter that is written on company stationery, since it commits your company to what you have written. When stating your opinion, use I; when presenting company policy, use we.
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.