To tie a necktie, one of the most popular and versatile methods is the Four- in-Hand knot. Here's a simple step-by-step guide:

1. Place the tie around your neck, with the wide end on your right side, longer than the narrow end on your left.
2. Cross the wide end over the narrow end.
3. Bring the wide end under the narrow end.
4. Pass the wide end back over the front from right to left.
5. Pull the wide end up through the loop around your neck.
6. Finally, tuck the wide end down through the knot in front and tighten it by sliding the knot up to your collar.

This creates a slightly asymmetrical but classic knot suitable for most occasions. If a more formal look is desired, the Windsor knot is a good alternative but a bit more complex to tie.