When Wiggins announced that he had found the cab, Holmes asked him to invite the cabman up to their rooms. When he entered the room Holmes snapped the handcuffs on him and introduce him to Gregson and Lestrade as Mr Jefferson Hope, the murderer of Enoch Drebber and Joseph Stangerson. (A Study in Scarlet)

 

Holmes soaked a handkerchief in the creosote from the carboy in Bartholomew Sholto's chamber. He then pushed the handkerchief under the dog's nose and waited for Toby to follow the scent. (The Sign of Four) 

 

Athelney Jones mopped his face with a red bandanna handkerchief, while waiting for Holmes to return to 221B Baker Street. (The Sign of Four)

 

Holmes had a member of the Baker Street Irregulars stationed at Jacobson's Yard. He had a handkerchief to wave if the Aurora was about to leave the yard. (The Sign of Four)

 

Dr Watson wore a hat when he went out. The first such occasion was when he escorted Miss Morstan to the Lyceum Theatre. (The Sign of Four)