Margot Robbie began training six months prior to shooting the film. Her training routine included gymnastics, boxing, weapons training, aerial silk training, and learning to hold her breath underwater for extended periods of time.
The helicopter crash scene was the last to be shot, just in case any of the cast members got injured, which would delay filming.
Margot Robbie revealed at San Diego Comic-Con International 2016 that although the cast members of the squad had extensive rehearsals together, she and Jared Leto did not rehearse prior to filming their scenes. She and director David Ayer felt it added to the unpredictability and madness of Harley Quinn and the Joker.
The majority of the cast and crew got the tattoo "SKWAD" in honor of this film. The tattoos were even applied by some of the cast members, Margot Robbie and Will Smith.
Margot Robbie did the majority of her own stunts. Writer and director David Ayer stated her stunt double spent more time sitting around in the trailers than actually performing stunts because Robbie wanted to do them herself.
Robin Atkin Downes: When Deadshot is first introduced, he's been hired by a mobster named Angelo to carry out an assassination. Angelo's voice, heard over the telephone, is provided by Downes, who played Doomsday in Batman v Superman: Dawn of Justice (2016).
David Ayer: The dead pig that Jared Leto sent the cast is actually seen when they're doing the feeding sessions to the inmates as they drop the dead pig into Killer Croc's cell. It was later confirmed that this was the actual pig that was sent that was used in the film. In the extended cut of the film, the director has a cameo as the guard who drops the pig into Killer Croc's cell.