Rarely.
I like the freshness and shape and color intensity (especially black) of new clothes. I try hard to preserve them - I feel like they go downhill from the first wash onwards,
Besides, NYC neutralizes a girl's neuroticism about clean. Think about it. I buy a new shirt. It might have germs. I wash it. I put it on. I leave the building. I enter the subway. I touch the subway banister. WAIT. How many germs are on that subway banister? I go through the turnstyle. It touches my shirt. AAAH! NEW GERMS!!!!!