We get this question all the time. How does one dress for a headshot. The answer is easy: Dress like you are going to meet your best client.
A headshot is the first opportunity to make an impression. Does your company service a more traditional industry? If yes, wear a suit. Does your audience value creativity? Then something less traditional can work.
Whatever you put on make sure it is clean and free of wrinkles. Most importantly, make sure you feel comfortable and confident.