Women have a lot of flexibility in their wardrobe that can be a good and bad thing. The standard job interview dress for women is still pretty much the same thing as men, a dark navy or grey suit or other conservative colors. Women should avoid wearing a dress.
Make up should be very minimal with both the lipstick and nail polish being conservative tones. You should have pantyhose with no runs and also conservative in color. Try to have a briefcase and not a purse.
As stated before suits are the best choice for the job interview. Employers seem of a split mind whether it should be a pantsuit or skirted. Your skirt length should always be below the knees and NEVER far above the knee. No matter what anyone tells you.
The best patterns for your clothing are solids, soft plaids, tweed and the like. Colors are also best to be conservative; blue, grey, charcoal, khaki, etc.
When it comes to shoes women should stay with a conservative pump with a mid level heel. Extremely high heels are a definite no no. Your shows should complement your outfit and not be the center of it. It should also go without saying that no sandals or sneakers for a job interview.
Women should always wear hosiery on a job interview. Even though you will not on the day to day job you should for your job interview. They should be a natural skin color and stay away from white.
Of course your hairstyle should also be conservative and easy to control. You do not want your hair to be the focus of attention. You want your skills and experience to be. If necessary wear your hair up.
Finally avoid any bright lipstick and subdued makeup. Wear deodorant and go light on the perfume. Brush your teeth and use mouthwash before the interview. There is nothing worst then having an interview with someone with bad breath. I have personally cut interviews short because I couldn’t take someone’s breath or perfume. They could have had the qualifications but I wouldn’t have known because I needed to get fresh air.
Even though women have more flexibility with their wardrobe for the job interview the overall theme is conservative. The primary focus of how you dress should be that of not taking away from your skills and experience that make you the right candidate for the job. By being neutral and conservative in your attire will help you achieve that goal.