I have previously tried wearing a pocket square but, being a bit of a perfectionist, I was never happy that it would sit “just right” all day long – especially when I take my jacket on and off throughout the day.
Then I stumbled upon this pocket square holder on Amazon. It works a treat, you fold your square to the pattern you want, put it in the holder then put the holder in your pocket. The clasp is a bit tight, this may loosen off over time but better to be too tight than too loose.