For example, Princeton or Ivy League's after-show party? (6)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

HAIR (show), DO (party). It was easy enough to work out what was going on here but the hair-style in question is not listed in any of the usual sources and not widely known in the UK, I imagine, so I wonder what the clue is doing in The Times of London. My AI assistant advises:  The Ivy League haircut is a popular choice for students and alumni of Princeton and the Ivy League in general because it is a classic, sophisticated, and versatile haircut that is associated with success and achievement.