This is an interesting question as you might automatically think I will wear a suit! The work place has changed and dress codes are less formal, however, first impressions count.
You should always look smart whether a dress, skirt/trousers and blouse for females or Smart trousers and shirt for males. Everything should be ironed with no creases. Shoes polished and no scuffs on tips or heals.
For the more formal look ladies, can add a Jacket matching your dress or skirt and guys a tie and jacket.
When you are doing your research try and get a feel for the type of company you would be joining and dress accordingly.
NEVER WEAR JEANS, TRAINERS OR RIPPED ANYTHING!