A gentleman never resorts to clip-on neckties (an oxymoron if ever there was one). Instead, a gentleman ties his own ties. The most basic knot is the full Windsor, but the most useful knot may be the half Windsor. It’s especially useful for big men who want to wear ties of ordinary length. Remember, the tip of your tie should come to your belt but not hang below it. Here’s a guide from The Art of Manliness.