There's more to long-sleeve T-shirts than having a little more fabric around your forearms. Not only are they equipped to cope with changeable weather (and an excellent jumper substitute for when it's not quite cool enough), they're also an easy way to lend an outfit some streetwear edge, and can be much more flattering on your physique (whether you're looking to accentuate a bicep bulge or are self-conscious about your mid-section) than their short-sleeve counterparts.