imagine your report would be like a pyramid. You are at the bottom, with the broad base of knowledge of the subject. Then as you move on up the pyramid, you are narrowing down to the final point (the conclusion). The narrowing down should therefore be the main body of your report, with the broad bit being something like 25%.
and before anyone asks about that strange way of explaining something, I am not drunk or drugged up. This is a bit of advice that was passed on to me, and it has helped me out.