We're living in well-dressed times. More than any time in the past decade, men have lately been taking more pride in their appearance and the image it projects. While it's important to have some natural ability in matters of attire, it's equally (if not more) important to learn the rules of clothing to as to manipulate them and, eventually, tastefully break them. The first concept where men can generally use some guidance is coordinating a tie and pocket square.
First and foremost, note usage of the word “coordinate” as opposed to “match.” To match your tie to your handkerchief is poor form for a couple of reasons. For starters, it draws the viewer's eye horizontally across your chest and takes attention away from your face, which does you no favors at all.
Secondly, it lacks sophistication. Certain things make sense to be sold in pairs: shoes, socks, cufflinks, the Olsen twins on the black market. Ties and pocket squares, on the other hand, should be sold separately. Anyone selling them in matching sets is a clothier of dubious distinction and is not to be trusted, much less supported with your business.
Successful coordination between ties and hankies isn't all that difficult if you think of both in terms of color and pattern. For example, let's say you're wearing a red/blue striped tie like I am in the picture above. If you'd like to coordinate the stripes, wear a handkerchief with blue/white stripes or a plaid, as the straight lines of the plaid sync up nicely with those of the striped tie. If you'd like to focus on color, you can do solid red, solid blue, blue with red dots, red with blue paisley, etc. As you get a bit more advanced, you can start playing with complementary colors: that same red/blue tie can take a purple pocket square, for example, because blue and red make purple. For more insight on this, all you have to do is remember your primary (red, blue, and yellow) and secondary colors (orange, purple, and green). Most of these colors will play nicely with the others, depending on shade.
As a guideline, remember that a white pocket square goes with anything and is to be worn exclusively with semi-formal and formal wear. Finally, keep in mind the Rule of Two, oft-stated as “one for blowin', one for showin'.” The idea here is that a gentleman has two handkerchiefs at all times: one for show in his breast pocket, and one in his back pocket should he or someone else need it to clean up a spill, wipe away sweat, and even plug up a nosebleed. Perfect for the pugnacious gentleman, eh?