You may not have given much thought to your socks, but believe it or not, people do notice them. You could be wearing the most fantastic pair of shoes, but if the choice of socks is off, it up-ends the whole ensemble. When choosing socks to match your outfit, the common wisdom is that they should coordinate with your pants, as a way of elongating the leg. Of course as with anything else, there are exceptions to the rule. With a monochromatic look, or with khaki trousers and brown shoes, show some personality by sporting a colored sock in a solid or pattern. If wearing patterned socks appeals to you, and you want to take it a step further, select a motif that keys into and complements another element of your outfit: the pattern in your tie, sport jacket, or shirt for example. And whatever you do, make sure your socks are long enough such that when you sit down and cross your legs, your lower leg remains undercover.
Here is a basic combo I like:
And here's one that's a little more "advanced":