The middle button on a jacket should always be closed. The upper one depends on your mood. The lower one should never be closed.
The tip of your tie should reach your waist and cross it just a little.
If you are wearing a shirt without a jacket, you don’t need a tie.
If you tucked in your shirt, you should wear a belt.
Your socks should be long enough that your naked legs aren’t seen when you are sitting.
All visible tags on clothes should be cut off.
Your belt should be the same color as your shoes.