Hide
The Doctors bowtie doesnt usually come in handy, except as a fun prop. But once he got married with it (sort of), and in Hide he finds a more practical use.
The Doctors bowtie doubles as a lock for the door, which is pretty clever when you think about it. Too bad the door wasnt there a minute later Claras first solo trip on the Tardis is also holds extra entertainment value on the repeat view. At first it looks like she may be flying it (very badly)
Then it looks like shes just hanging on for dear life
But by the time she reaches the Doctor shes letting out the whoops and laughing: shes riding the Tardis through a deadly pocket universe like its a roller coaster!