The X-Men are the most popular super team of all time, and they've had multiple covers that changed comics forever.

*Any of these guidelines can be ignored if you have a specific effect in mind, but only if you know why you're doing it. All these points may seem painfully elementary, but if they weren't ignored so ...

Comic book fans are mourning a legendary artist who made his mark on major franchises belonging to Marvel Comics, DC Comics and others after his passing over the weekend.