2. Be Prepared To Kill
I remember hearing something that Steven Moffat once said of fellow writer Russel T. Davies: he likes to create wonderful characters and then melt them. Seriously, when you think about both Daviess and Moffats careers as showrunners, the body count of Doctor Who must be one of the highest for any childrens show. And thats not counting the 1963 run: classic episode The Caves of Androzani infamously killed off all but one of its entire cast! Not that every episode needs to resort to these extremes. But the well-timed death of a likeable character is a tried and tested way to grab the audiences attention and invest their emotions in the episode. Not only that, but it makes rare moments like the Doctors ecstatic cry of everybody lives! in The Doctor Dances much more heart rendering.