Rose Bailey (Chronicles Of Darkness, Cavaliers Of Mars and much more) offers some suggestions in the Sell Me On Or Off Doctor Who thread on RPG.net:
If I were going to write a Doctor Who adventure design guide, it would go something like this.
You have a setting, which can be space station or a place in Earth history or whatever.
You have a doom, which is how a lot of people in the setting are going to die if the PCs don't do something.
You have locals, the people in the setting that the PCs will meet and immediately become entangled with. They have at least one human complication, a relationship issue which impacts their ability to work together in the face of the doom. Parent/child conflicts are often good, so are struggles between morality and expedience, and distrust between coworkers is surprisingly effective.
Your doom has one or more minions. Minions usually have a distinctive look and kill or otherwise harm people in a distinctive way. You can't stop the doom by killing the minions, but the minions do most of the harm and present the most frequent threats to PCs and locals over the course of the adventure. Minions will often spend the early part of the adventure killing off locals one by one.
When the PCs fail, the consequences usually fall not on them but on the locals.
Finally, after the first few scenes, the story takes place as a crisis, encouraging or forcing the locals to work with and place trust in the PCs when they ordinarily might not. Locals are most often suspicious of PCs at the beginning and toward the end, while accepting them in the middle.
