Define the audience of your report and executive summary. Think about the specific interests and time constraints of your audience. For example, if your audience is your boss at work, he may lack the time necessary to read a long summary, and only be interested in reading short, important bits of information.
Identify the conclusion of your report. The data that you studied and used to create your report will have led you to form conclusions. The conclusions of your report should be used as the thesis of your executive summary. The thesis should clearly and concisely define the most important aspect of the report for your reader toward the beginning of your executive summary.
Determine the most important facts about the report that you feel your audience would be interested in and need to know. For example, difficulties you faced along the way may be more important to some audiences than a discussion of the specific materials you used to reach a conclusion.
Write concisely to include all of the important information and conclusions from your report into less than one page. Get straight to the point, without using a long introduction and conclusion that may be used in a longer report. Identify only the key facts and skip any details that aren't necessary.