SUIT ACCESSORIES: POCKET SQUARE
To some people, the pocket square is an unnecessary, over-the-top accessory. To other, a handkerchief is to blow some boogies in there. Both of these options are entirely incorrect.
We know, a pocket square looks like the brother of a fancy handkerchief, but it is not designed for nasal utility. It is a style choice you should make as often as possible. A suit and a tie with no pocket square pretty much tells the world I had to wear a suit, so here it is, move along and leave me alone."
Choosing a pocket square is not as simple as matching it with the choice of tie you made. Instead of matching, try coordinating them. Patterns in different scales (polka dot pattern and pin dot), a pattern and a solid in the same color family, or complementary colors are all pretty easy to put together.