Just a few years ago, Isla Fisher was a little known actress, perhaps most famous on British shores for playing Shannon in Australian soap Home & Away. That all changed in 2005 when she played Vince Vaughan’s crazy love interest in Wedding Crashers. Today, she’s talking to Entertainmentwise about her first lead in a Hollywood movie, the Jerry Bruckheimer-produced Confessions of A Shopaholic, based on the novels by Sophie Kinsella.

ENTERTAINMENTWISE: You play Rebecca, an out of control shopaholic, in the film. Is it true you requested 5-inch stiletto heels for the part?

ISLA FISHER: I did! I thought there’s something funny about a shopaholic buying ridiculously high heels and tottering through the comedy, I thought it would be amusing. It was less amusing, actually, when I had to do it every day!

EW: Was there much research involved for the part?

IF: My girlfriend from high school is a journalist, so that was cool. I also researched the shopping aspect by visiting some ‘over-spender, under-earner’ groups, who were shopaholics but whose lives, sadly, have become unmanageable because of the addiction. But I don’t want to dwell on that, as this is supposed to be escapist fun!

EW: What was it like working with Patricia Field (costume designer on Sex And The City, Ugly Betty and The Devil Wears Prada)?

IF: I really enjoyed working with her. I’m not a fashionista, I don’t have much experience of that world, but I was educated by the end! I felt that even my own style is a lot braver now, so I really enjoyed working with her. She has this great sense of fun that she brought to the character.

EW: Did you keep any of the clothes?

IF: I didn’t keep anything. I loved wearing the costumes, but in the end they’re Rebecca Bloomwood’s costumes.

EW: Finally, does your partner (‘Borat’ star Sasha Baron Cohen) have any advice when taking on comedy roles?

IF: Actually, Sasha was the reason I got into comedy. I was auditioning for a lot of dramatic roles and having no success at all. I was losing confidence in my abilities when he recommended that I do comedy. He always felt I was really funny, and when someone as funny as him recommends that, I listened to him and auditioned for ‘Wedding Crashers’ which was my big break.

Confessions of a Shopaholic is out February 18 - read the review here