The director Rachel Talalay was asked about how they shot the now iconic moment where Cyberman Bill carried the prostrate Twelfth Doctor to the TARDIS in The Doctor falls (season 10, episode 12). After reading a lot of inaccurate speculation, she responded with this detailed video explaining how it was done.
Storyboards: the awesome Mike Collins/Freakhouse Graphics.
Custom necklace from @lucytalalay on Instragram