The opening part of any preaching event is vital. A good introduction sets up the message for people to be able to benefit from the preaching. A bad introduction confuses people and sets them up for a 30/40 min (or how ever long) doze. So I want to mention two things that I believe are crucial to have in an introduction.
Engage. The congregation must be engaged with. Most importantly they must be convinced that you are going to bring a message which engages with them. It is no good to just to drift into a message. Rather, there must be a determination to convince the people that you have a message that they must listen to.
Direction. You must give the people an indication of where the message is going. Generally this will mean that you will place the passage you are preaching from in context. A brief indication of where the passage is situated in scripture and what has occurred immediately before are likely to be appropriate.
Most importantly though, you need to say what you are planning to do. This may mean giving the gist of what is ahead; it may mean giving an indication of the points that you plan to cover. Alternatively an approach may be adopted whereby the congregation are longing to know what answer you are going to give to a vital question which you have set before them. They know from the way you have constructed your introduction that your purpose is to answer that question.
So fellow preacher I feel we must work on our introductions in order that they would be properly crafted in to gain maximum benefit under God for the people hearing the message.