You need to prepare by improving your general writing skills.

Make sure that you:

 

Know, in general, the appropriate format and style for a standard shot message, business letter and business report.

Know how to select the appropriate information to be included in your document

Know how to structure the information in clear and logical sections

Know how to write in a style appropriate to the type of document and reader

Know how to use a range of basic grammar and standard phrases accurately

Keep within the time frame for the task