Stan's (1st AD) apartment was transformed into Dylan and Erin's apartment on the first day of filming and included several paintings/posters created by Rachel and Ceirra to be displayed as Dylan's artwork and Erin's photo collection respectively. In order to maintain continuity for the mess that Dylan creates, the "destruction of the living room" flashback sequence was broken down into 5-6 different setups. Each setup was done in one take.
The film was shot over a two day period, with the script split into two acts. This gave Rachel and Kelly the freedom to let loose and try new things with their characters as they were playing out the scene like a live performance. With this, Ceirra (director/writer) was able shoot continuously by moving around their blocking in order to grab different shots from different angles within the takes.
The role of "Erin" was originally written as a guy named "Aaron". Once Kelly (Erin) had shown interest in the project, the role was immediately changed making Dylan and Erin a lesbian couple.
Rachel (Dylan) and Kelly (Erin) went through an intense 4 day rehearsal period where they broke down and rebuilt the relationship between Dylan and Erin both intellectually and emotionally. During one of the rehearsals, Rachel and Kelly spent almost three hours recreating memories between Dylan and Erin through improvisation, ranging from how they first met to their last big fight before the film is supposed to take place.
Because Dylan is a heavy smoker, Rachel was smoking herbal cigarettes during the entire shoot. She went through 2-3 packs in order to maintain continuity. The "whiskey" she was drinking was water with caramel food coloring.