There are many things to consider when considering the communication requirements of your target audience

There are many things to consider when considering the communication requirements of your target audience, such as, whether they are an internal or external audience. When communicating with an internal audience, you may not have to be so formal and can afford to use office jargon and abbreviations that your colleagues will be familiar with. You would need to be more formal with an external audience to ensure you keep to a high standard of professionalism, using abbreviations with an external audience would not be appropriate as their level of experience and knowledge would not be the same. Your audiences level of knowledge and experience will impact on how you choose to communicate also, people with a low level of knowledge on the subject, such as new colleagues or potential clients would require you to start at a low level and go into more detail than you would have to for experienced colleagues.
Understanding the aim of your communication is also something you should consider; as well as the impact you are hoping to have on your target audience. Is your aim to sell a product, implement a new strategy, educate new colleagues, all these various aims will require different methods and styles of communication.
Deciding which is the most appropriate and effective method of communication will determine how you deliver your message, deciding if is it going to be a written communication in the form of a letter, email, note or report or delivered verbally via a phone call, a face to face meeting, small group discussions or giving a presentation. Considering the tone and style of your communications is also important, this will depend on the message you want to convey to your audience. A relaxed and informal tone and style would involve the use of more relaxed and casual language and even meeting arranged in a more ad hoc manner. If the message is of a more serious nature, and you want to get it across with maximum impact, more formal language and a structured, planned meeting would be more appropriate.