For myself, I think it's just as much how to word things properly to most effectively get your point across, as it is to be ready if your report has some kind of backlash or isn't seen the way you meant it. You need to be mentally prepared to handle the response you get back, even if it's no response at all after you spent many hours putting a report together and worrying about how to make it just right. Obviously this will change depending on how important what you're reporting on is, and whether your work contributed to that report's findings.