I guess I have a tendency to work with mostly new plays, which I like because it's all brand-new ideas.

Mimi O'Donnell's path to New York City and a career in costume design was not a direct one. For one thing, she attended fashion school, not costume design school, in her native Philadelphia. But even before that stint — at the Philadelphia College of Textiles and Sciences, now called Philadelphia University — she considered the fields of education and dentistry.

“I spent my freshman year at school in Lancaster, PA, doing secondary ed,” O'Donnell says. “It was something I enjoyed for a time, but then I spent time student-teaching, and I realized I didn't want to do that. So I took a year off and worked in a dentist's office as a hygiene assistant. But that wasn't really what I wanted to do either, so I started taking classes at Philadelphia Textile.”

O'Donnell graduated with a major in fashion and a minor in textile design, then interviewed at a few fashion houses in New York, but she ended up working at the Arden Theatre Co. and Walnut Street Theatre in Philadelphia as an assistant designer or stitcher. “It sort of clarified that this was what I wanted to do, instead of doing fashion,” the designer says of the experience.

After a few years working locally, O'Donnell went to the Williamstown Theatre Festival in Massachusetts in 1993 and worked as a first hand in the costume shop. “That was the first time I was completely surrounded by it, immersed in the whole costume thing,” she says. “I said, ‘This is what I want to do and I want to move to New York.’ It was a crazy, crazy place to work, because you do 10 shows throughout the summer; it's practically like opening a show every week.”

One person O'Donnell met at Williamstown was Playwrights Horizons costume shop manager Therese Bruck, who called her in 94 and offered her a job in the wardrobe department. O'Donnell took the job, and worked on several productions there, such as A.R. Gurney's A Cheever Evening. O'Donnell says one of the best things about the wardrobe job was that it freed her up to work on design projects in the daytime; her first New York costume design project was for a production of Hesh by actor Ethan Hawke's company malaparte.

“After that, I continued to take every job I could,” O'Donnell continues; she hooked up with the LABrynth Theatre Company in 1999, doing the costumes for In Arabia We'd All Be Kings, which was directed by Philip Seymour Hoffman, then worked again with Hoffman on Jesus Hopped the A Train in 2000. O'Donnell also worked with John Patrick Shanley on his new play, Where's My Money? this past June, which is moving to Manhattan Theatre Club in October.

“I guess I have a tendency to work with mostly new plays, which I like because it's all brand-new ideas,” O'Donnell says. She enjoys the rehearsal and tech processes: “I realized that's where my answers are; if I have any doubts about what they're going to wear, I just go sit in rehearsal for a while and it comes to me.”

In addition to her theatre work, O'Donnell has a steady gig as assistant designer to Tom Broecker on Saturday Night Live. She says the SNL schedule leaves her plenty of time to work on theatre projects. “It's 20 weeks out of the year, we have three weeks off at Christmas, and a lot of times we'll have two weeks on, two weeks off,” she says.

“We get the scripts on Wednesday night, then we have three days to get it together,” O'Donnell says of the hectic SNL pace. “You definitely hit the ground running on Thursday morning, and throughout the next couple of days, they're rewriting and recasting, so where it was five people in a sketch, suddenly it's 20.” O'Donnell adds, “When 11:30 comes around and they say, ‘Live from New York,’ there's definitely a buzz in the air.”

While O'Donnell doesn't have one specific mentor in the business, she says she's learned from the various costume designers she's assisted. She says of Martin Pakledinaz, with whom she worked on The Life as third assistant, “Once an actor comes into his fitting room, if his sketch isn't fitting on that body, he's completely willing to toss it out the window and start from scratch, start anew. He may have been the first person I saw do that, and I thought, that works for me.” O'Donnell adds that she's learned a little something from every designer she works with, including Paul Tazewell, Constance Hoffman, and Beth Clancy.

In August, O'Donnell did summer stock, clothing Estelle Parsons and Judd Nelson in a production of The Cocktail Hour at the Cape Playhouse in Cape Cod. Her fall schedule is rapidly filling, too; in addition to Where's My Money? and SNL, she will be working again with Hoffman on Rebecca Gilman's The Glory of Living at Manhattan Class Company. Look for that to open in November, and look for O'Donnell's modern, flexible design there and on a television, live, near you.

Photo: Andrew French