Clean hands and nails are a big plus. Avoid white athletic socks with dark suits. If you have one, try to cover it up. Leave any earrings, nose rings, tongue studs, etc. at home. If you have a beard or mustache, make sure it is trimmed and well groomed.
Some experts recommend a clean-shaven look for job interviews.
Do wear nylons. It puts that finishing touch to your outfit. Make sure your shoes are clean and are professional. No spike heels. Get a manicure.