As the saying goes, a first impression is the most important impression you'll ever make. And you get only one opportunity to make a good one. First dates become second dates or not, business deals are made or broken, and friendships are formed or fail to materialize—everything hinges on that all-important initial meeting. Of course, these days we make initial contacts over e-mail or through social media. It could be months before you ever meet in person. And while that electronic communication shapes an opinion of you, it's the face-to-face interaction that forms a lasting impression. Here's how to give yourself an edge.