There are no special rules that can be given for precis-writing, but a few guidelines can put you on the right track of how to condense a lot of information. Before you prepare to write a summary, it is important to scrupulously understand the contents of the article or report you are working with.
When you prepare your summary, first of all, understand the content of the article. Read through the whole passage carefully to gain a general idea of the trend of thought, and decide what would be an appropriate title. Re-read it until you are satisfied that you have thoroughly grasped and digested its meaning.