It is essential that you present yourself in a neat and clean manner as they say you are judged before your interview even starts by the way you dress.
Some easy tips to remember are -
Never wear clothes that are too tight.
A neat clean suit is suitable both for male and female.
Clean shoes and not too high a heel for ladies is appropriate.
Freshly clean manicured nails as well as a tidy hairstyle is another point to remember.
Finally, don't chew gum or go heavy on the perfume or after shave.