The movie, which also features Ranveer Singh, is directed by Vikramaditya Motwane of "Udaan" fame.
"'Lootera', in terms of look and character has been my toughest. I hope people like it. Working with Vikramaditya was like going back to school. He is a wonderful director in terms of getting out a performance. Going back to 1950s is not an easy thing to do," she said.
"Lootera" is slated to release in 2013, but before that, Sonakshi's "Dabangg 2" will hit the screens around this Christmas.
Talking about her character in "Dabangg 2", she said: "The character will be more mature this time. It's a continuation of the story. They will be taking the married life forward."
Sonakshi says she believes in healthy competition with her peers. According to her, concentrating on your own work is the way to achieve success in the industry today.
"I believe in healthy competition. I find certain actresses very good and fresh on screen today like Deepika (Deepika Padukone), Anushka (Anushka Sharma) and Parineeti (Parineeti Chopra). Everyone is here to do hard work and a good job. I don't try to go ahead of them. I don't think of it like that. I think minding your own business is the right way to go," she said.
Sonakshi is eagerly waiting for the release of SOS, which also features Ajay Devgn, Juhi Chawla and Sanjay Dutt, Nov 13. She plays a typical Punjabi girl in the film and enjoyed shooting for it.