8. T-Shirts. These are excellent for layering and are a basis to just about any wardrobe (can be worn under a button-up shirt worn with a suit, or under a blazer and some trousers).
9. Trousers. Most jobs don't allow employees to wear pants, and trousers are casual and not as fancy as dress pants, or pants that are part of a suit. Even if a job allows a man to wear denim at work, at least try not to look like your 15-year-old nephew when you are wearing them.