This style, if you wish to make a dazzling impression.
I don't know as I've never worn a bow tie in my life!
You never had an occasion to wear a tux?
@Tink : Not that I can remember!
I would say that most associate bow ties with special events, celebrations and fashion trends, while some prefer to wear them any time.
Quite a few celebrities have been known as "bow tie wearers":