Decide if a memo needs to be sent. If you need to update several people on your team about an important business matter, then sending a memo is an excellent idea. You may even want to send one if you're communicating with just one person if, for example, you want or need to have a written record of your correspondence.
Identify your purpose for writing. Depending upon your specific purpose, the content and organization of your memo may change. Most types of memos are written for the following reasons:
Narrow your topic. You may be juggling a lot of projects and be tempted to send a memo updating your colleagues, superiors, or clients on everything you're currently working on. Keep in mind though, that business memos should be focused on just one issue.
Consider your audience. The content, style and tone of your business memo will all be affected by the intended audience, so think carefully about everyone who will receive your memo.For example, you'll write a different type of memo if you're writing to your colleagues about planning a surprise party for the people in the office with summer birthdays, as compared to when you're writing your supervisor about the results of your months-long investigation.