A blazer does wonders to many a jeans / cords and top outfit. Except in the blazing hot summer, which it currently isn't in the northern hemisphere. And like Knotted said, cute (or nice) shoes but not sneakers. The other thing to try if your wallet can afford it is to go to a store like Banana Republic or Black Market / White House and plead for help - both have dressed me for special occasions or job interviews.