Whether you are a seasoned writer or not, crafting an effective keynote speech is likely to rank among the more challenging assignments that you will ever receive. Without structure, your speech is dead air, yet you must also win over an audience of total strangers with humor and verve. Small wonder that many people leave the job to someone else--but with a little bit of common sense and attention to detail, creating a great keynote speech is less intimidating than you may think.

Do Your Homework

Know your audience. A police convention is probably not the ideal setting to call for legalizing marijuana, any more than a Baptist meeting offers a venue for debating the merits of abortion rights. You want listeners on your side from the get-go, so learn who they are. Doing this sort of homework minimizes the chances of walking unprepared into a hostile setting.

Research your subject as thoroughly as possible before writing the speech. Nobody expects a speaker to know everything, but getting a grip on your subject matter pays off in two ways. First, the research may take the speech in a totally different direction, to its benefit. A close review of the subject will also lessen the temptation to cram random bits of minutiae into the speech.

Plan on a 20- to 90-minute presentation, depending on the audience and type of event you will address. Always leave the audience wanting more, not feeling relieved that your presentation is finally over. Also, be sure to allow time for related events, such as a host's introduction or a question-and-answer session that may follow the speech.

Lay Down the Structure

Write a rough summary of the main message, along with two to five supporting points to emphasize above all others. Drawing on your research, jot down those points on 3-by-5-inch cards, followed by key quotes or anecdotes that you may want to use. Do not worry if the ideas come slowly or sound undeveloped. Getting them down on paper is the important thing.

After you establish your main theme and supporting points, begin developing an outline of your speech's structure. Knowing what you plan to say and how you will say it allows the freedom to improvise within a structure. A clearly defined structure also enables the audience to follow along without difficulty, while reassuring everyone that the ride will not be a rough one.

Find examples of other well-written speeches to help determine the structure you will use. Some of the more common approaches include the chronological overview, which works well in describing key events in your life. If you are taking on a social issue, a "problem/solution" approach may be the preferred model, or an overview of the past, present and future may work better.

Do not be afraid to show a little creativity. Express a major life-changing event--such as overcoming a major illness--as a journey from one distant place to the next. Or perhaps you want to couch your main points about taking on credit card debt as a "lessons learned" exercise. Whatever approach you take, make sure that the audience can follow along.

Drive Your Conclusion Home

Include a strong opening statement, followed by an anecdote, that lays out your main theme and explains your purpose. Connect with the audience members by explaining how their problems will be solved or how you will enlighten them about the subject. Lay out your credentials, because an audience naturally wants to know what makes you an authority. However, avoid trotting out a resume or an eye-glazing list of professional credentials. Make the point about your background in a couple of sentences, and move on.

Put your strongest points first, from most to least important. Sometimes, time constraints will force you to cut short a speech, but it will be easier to cut from the bottom than the other way around. Always include relevant examples, quotes and statistics to support each main point that you make.

Drive your main theme home with a vivid anecdote or story that underlines the conclusion you are hoping to impress on the audience. This is the final opportunity to convince your listeners, especially if the speech has been well received, so it is your job to provide the deal-clinching argument that their ears are seeking. Never leave an audience hanging.