A pocket square is the finishing touch that completes the fashionable man's ensemble. Without one, your coat pocket, it is naked. A well-selected pocket square should pop with a complementary flash of color, without detracting too much attention from the man who wears it.
"A gentleman always wears a pocket square."
The bad news is a solid-color silk pocket square will set you back at least $15. Considering the sartorial importance of this little piece of fabric, why shell out the cash for a mass-produced one when you can make your own custom square for eighty cents? (or, in my case, have your wife sew it for you?)
The primary advantage to DIY is being able to exactly match the color of the square to a color in your tie or shirt. Once you've found your fabric, there are two ways to sew it up:
the fancy way (which requires difficult rolling and stitching by hand), and the easy way (which involves ironing the side hems and sewing with a machine). Nobody will know the difference, except for you. Everyone else will be too busy admiring your classy outfit to notice that you didn't spend $35 on a hand-rolled pocket square.