 Many scenes were shot in advance . The producers disliked filming beforehand as they preferred " the audience to tell us what 's good and what 's bad . " They also were concerned that a flashback episode would be mistaken for a clip show , but felt it would be believable because they were " flashing so far back into the past . " According to Kauffman , certain scenes filmed in the apartment were shot in advance because " it was all over the place " ; the cast were tired and full and their energy levels were low . Special effects and costume changes meant " three or four scenes " were also pre @-@ shot to ensure the dialogue was happening in front of the audience . This was completed in two days . 
