The easiest way to tie a necktie is the method shown in this video. The knot it forms is slightly asymmetrical, but it’s appropriate to wear for any occasion, from work to a wedding.
Tie, collared shirt
With your collar upturned, drape the necktie around your neck so that the middle of the tie lies flush against the back of your collar, seam down. Hold the wider end of the tie in your dominant hand (and the narrow end in your other hand) and pull it down so that the tip rests about one foot lower than the tip of the narrow end.
Bring the wide end across the narrow end and clasp it with your nondominant hand a few inches below your neck, where the two pieces intersect.
Reaching under the narrow end with your dominant hand, grab the wide end and pull it behind the narrow end, back toward your dominant side.
Bring the wide end back across the front, where your knot is starting to form, and then, switching hands, bring it up through the loop between your neck and the tie and pull it all the way out over the narrow end.
Still holding the wide end, create a small loop within the knot with your other hand and, starting with the tip, push the wide end down through the loop.
Squeezing the knot gently with your nondominant hand, pull down on the narrow end with your other hand and slide the knot upwards until it touches the front of your collar. Center the knot. The tip of the wide part of the tie should the top of your belt buckle. (The narrow end should be shorter, and not visible in the front.) Flip your collar down.