All of the scenes in the movie are first takes. Adrian Tofei did multiple takes in the beginning, but then he realized that the first ones are always the most natural and authentic ones and decided to include only first takes in the final cut.
Adrian Tofei, who came from a background in method acting and theatre (Ion Cojar's method), partially improvised the movie in his hometown on a limited budget as director, producer, writer, lead actor, cinematographer, editor and other jobs usually performed by a film crew, he never used a camera before in his life, had no crew present during shootings other than him and the actresses, partially lived in character, met the actresses for the first time in character with the camera on and kept only first takes in the final cut. A language switch was used during filming to ensure the safety of everyone involved: speaking English meant everyone is interacting in character, and speaking Romanian meant everyone returns to be being themselves (with a few exceptions when the characters had to speak Romanian). Filming was preceded by months of preparation via emails and phone calls between Adrian Tofei and the three actresses.
One of the reasons why Adrian Tofei chose to make Be My Cat a horror movie was his theory that horror films put a mirror in front of the audiences, a mirror in which they see reflected their darkest and most violent subconscious impulses, and so they become aware of them and get to control them in real life, thus becoming better persons. He meant the movie to be a character study about the paradoxical human nature, a meta study about filmmaking and acting and a lesson in cinematic realism.
Adrian Tofei shot the movie with a Canon Legria HF G25 camcorder using the internal microphones. The laptop he holds in the scene with Florentina Hariton (Lenovo Essential B590) is the same one he later used to edit the movie. The editing program was Premiere Elements 12.
A language switch was used during filming to ensure the safety of everyone involved: speaking English meant everyone is interacting in character, and speaking Romanian meant everyone returns to be being themselves (with a few exceptions when the characters had to speak Romanian). This also allowed the actors to freely experiment interacting in characters during improvisation without the fear of confusions. A practical example was when actress Sonia Teodoriu unexpectedly called the police for real while improvising one of the scenes, surprising Adrian Tofei both in and out of character. The language rule they were using helped Adrian understand that Sonia called the police in character, not out of character on him personally, since she continued speaking English. The policemen who came understood the situation and just wrote a warning for calling the emergency number for no valid reason.