TELL ‘EM WHY YOU'RE WRITING, AND WHAT YOU EXPECT TO HAPPEN.
Surveys of top executives made by the American Management Association have repeatedly found that recipients' most important expectation of e-mails, memos, and reports is -- Why are they written and what result is expected?
It is also the rarest approach. How many times have you received a written message that does not reveal its purpose until the last paragraph, or the last line? Or ever? Nothing is more disconcerting or irritating, than to read a nasty surprise sprung at the end, “out of the blue”. It seems a rule of thumb that the more hesitant the writer is to state his/her purpose, the lengthier the document. State your purpose and expectations right up front. Say them first. ["This is to report on the shortage of widgets in Chicago, and to request authorization for emergency funding...."]
Don't waste everyone's time by "throat-clearing" before you get to the point. It helps readers to know right off the bat whether the memo is for info only, requests an opinion, or requires some form of action. If you adopt this straight¬forward style, people will start noticing memos from you over others', and appreciate your professionalism. Most of all, when you get to the point straight away, it says you respect the reader's time.