Cases:NO TIME FOR REAL CASES. THERE'S PORN ON THE HORIZON. (Either story begins just after a case, or incorporates a few legit-sounding details.)
Anderson:Not usually in story but inevitably mentioned with appropriate scorn.
Mycroft:Usually either very for or very against Johnlock. Either way he's kinkily watching the CCTV.
Tea:Everyone drinks at least half their body weight in tea during the course of a story. Even drabbles. You see that 800-word story? 400 of those words deal with making tea.
Milk:Getting the milk is a thing. It's practically a euphemism at this point. If Sherlock gets the milk, he's DTF. Or apologizing, and then offering his body as an extra form of apologetic-ness.
Mrs. Hudson:Ships Johnlock like a beast. Hell, she usually has some kind of Johnlockfucking-sense. She just KNOWS when they're hooking up and is determined to facilitate this/make it kind of embarrassing for them in a cute way.
Mummy Holmes:For not actually being in the show, she's surprisingly mentioned a lot. She's everything from a horrid bitch to actually a really loving rich lady who somehow just has these two weirdo sons.
Moran:Ditto, kind of. Moran is sometimes a woman, sometimes a man, sometimes seduces Moriarty/John/Sherlock/all of the above. Also somehow capable of holding 7 laser pointers I mean snipers in TGG.