Garrett Hedlund auditioned at a karaoke bar in Koreatown singing a Pearl Jam song. According to director Shana Feste, "It really wasn't the best showcase ever of his voice, but Garrett went to school for us. Literally, he took four months off and started learning how to play the guitar, took voice lessons, went to Nashville early, started working with Nathan Chapman, a record producer in Nashville who produces Miranda Lambert. I mean, he became a country singer."
Garrett Hedlund heeded Tim McGraw's advice to "live and breathe country music" and to approach the role from the perspective of a singer trying to make it in the business, not an actor tackling a role, so he stayed in a cabin on McGraw's ranch where he had guitar rehearsals.
Gwyneth Paltrow stated in an interview for Chelsea Lately (2007) that she considered it challenging to portray the character of Kelly Canter. To prepare for the role, she emailed her Ironman castmate Robert Downey Jr. (who's been sober for a very long time) for help understanding addiction and rehabilitation, and he wrote her back "the most amazing email" which really helped her.
Chiles states that her parents were in prison. Leighton Meester's mother gave birth to her while an inmate in prison. She was able to give birth in a hospital and cares for her for 3 months in a halfway house before returning to prison.
In real life, Garrett Hedlund and Tim McGraw are great friends. McGraw is godfather to Hedlund's son, Rhodes.