Originally Posted by Holdfast
If I'm wearing a jacket, it has a pocket square in it.
That's my answer as well. There are some "detail" elements of outfits that I include or not include based on my instinct that day (bouttonieres, for instance). But I always wear a pocket square in my jacket, even if I'm on the rare occasion going tieless (at a summer cocktail party, say). I have more than sixty in my collection, and I fold them every imaginable way.
The compliments are frequent! In fact, one of the main reasons for wearing a pocket square (beyond the simple fact that I like them), from my sales guy's point of view, is to have an element in your outfit that people can comment on or ask about. If worn with a friendly air rather than a snobbish one (smile!), items like pocket squares, bouttonieres, hats, spectator shoes, etc., make one more approachable, not less.
Once a conversation has started, I may be on the way to having a new client, a new networking contact, a new source of referrals. If not, I've had a pleasant encounter and an ego boost. Win-win.