If you're like me and don't know how to tie a necktie without some prompting from somebody else, you know how it feels what it's like not knowing a basic skill (well, basic for some). As someone who is usually clad in a T-shirt and jeans I lose practise and forget pretty easily.

This knot is called the Four-In-Hand. Since it's the only one I know, I use it all the time. For today's etiquette^[1], it is acceptable for most occasions, but not the most formal of events (in those cases, you'll probably have a bow tie with a tuxedo).

Note: When I say "over" I mean farther away from your chest.
Also Note: These pictures are what someone else would see when if they watched you tie the necktie. This knot works both ways so if you do it backwards, nobody's going to notice.
Yet another note: I am the first to admit that I draw badly. The illustrations are not exactly what you'll see when you do it yourself.

• Place the tie around your neck so both ends are "pointing" down and that the wide side is on your left. The wide end should be lower than the narrow end.
  
  
  
  
• Make an X near your neck. The wide end should be over the narrow end.
• Pinch the crossing point between your thumb and 2 fingers with your left hand. Your fingers and thumb should be pointing straight up.
  
  
  
  
• Circle the wide end 360 degrees clockwise (looking down) over your thumb and fingers, but don't put it through the "V".
  
  
  
  
• Now, bring the wide end up through the V from behind.
  
  
  
  
• Push the wide end though the space occupied by the fingers.
  
  
  
  
• Now, you'll have to pull it tight and adjust it, If the narrow end is longer than the wide end, then you'll have to start over. The wide end shouldn't go down any farther than your belt (when standing).
• Now, you'll have to keep repeating these instructions until you get it right. Don't worry though, you'll soon get better at it.