A two-piece matched suit is always the best and safest choice. Don't combine a suit jacket with pants that don't match. Standard colors include black, navy blue, and dark grey.
Wear a long-sleeved button down shirt, even in the summer. Choose white, solid light blue, or a simple stripe pattern. Classic or narrow straight point collars are standard and give a clean, polished look. Since this is an interview, tabs and pins are not necessary.
Tie styles come and go. Select good quality silk ties that are solid dark colors or simple patterns. Stray away from fashion extremes, including the bow tie. Remember this is strictly interview attire and your style may change once you have received a job offer.
A black or cordovan leather belt is essential to complete your look. Your belt color should always match your shoes
Wear dark socks, preferably solid, and mid-calf length so that your skin does not show when you sit down. Black or cordovan, leather, lace-up dress shoes should be worn to the interview. Even if not worn daily on the job, this is a good investment for future occasions.
Accessorize with a classic watch, but not a sports watch. If you are applying to conservative industries, do not wear earrings. It is always professional to bring either a briefcase of portfolio with polished copies of your resume and/or business cards.
Shave the day of your interview. If you wear facial hair, it should be well groomed. Nails should also be clean, cut and polished. Avoid strong scented aftershaves, hair gels, cologne and deodorant. Keep in mind that people have allergies and sensitivities.