It used to be that if you were a man who worked in an office, you wore a suit and tie. Simple (if a little boring). Then came casual Friday. Now, even banks have relaxed their dress codes to allow for business casual. Which is great news. Unless, of course, you have no idea what actually qualifies as business casual, an all-too-common problem. Luckily for you, we've got some easy-to-follow guidelines that will keep you looking stylish, comfortable, and professional. From the right sneakers (yes, you can wear sneakers!) to how to properly dress up a pair of jeans, here are eight rules to make sure you don't sacrifice the "business" part of business casual.