Let the overall appearance be a little formal and yes, very tidy. Make sure your trousers are well ironed, don't forget to put on the belt. Generally anything except prints should be fine for the shirt. A plain white cotton shirt, nicely ironed, will almost always be the safest bet. Shoes formal or semi-formal, shining clean if leather.
Sports shoes are out of question.
Try not to wear any perfume, a mild one would do if you feel like, but never a hard one. Apply atleast an hour before the interview. Keep to a conservative hair-style. Women should preferably wear a light make-up. The jewelry , if at all worn, should be light and tasteful.