Think about it from the employer's perspective - if you were hiring an intern or professional employee, would you be more impressed with: a student in a business suit or a student dressed in jeans and a t-shirt? The basic rule is to dress one step more professionally than what you would wear on the job. Often, this means you will dress in business professional (a business suit) for career fairs, interviews, and other interactions with employers.
Masculine: conservative and tailored suit, tie in a muted color, polished shoes and well-groomed
facial hair
Feminine: conservative and tailored suit (either with slacks or skirt), closed-toe shoes,
subtle jewelry, make-up and accessories
All: suit should be a neutral color. Consider a professional briefcase or purse. Shine
up shoes.
Masculine: slacks, collared shirt and/or tie
Feminine: slacks or skirt, collared shirt or professional dress
All: avoid jeans, shorts, tennis shoes, and open-toe shoes