Take one look at Kevin Smith: He's a balding fatty who wears a hockey jersey, shorts and slippers year-round. Not a likely source for life advice. But take a second look: He changed filmmaking forever when he was 24 with the release of Clerks, and since then has gone on to make nine more profitable movies, runs his own production company, wrote a bestselling graphic novel, and has a beautiful wife and kids. So he must be doing something right. As...