For a professional headshot, how should I tie my tie?

The knot in your tie is right in the middle of the photo and while it should not be the focal point, if it is not tied right, it can look sloppy.

My suggestion is the Windsor.

I have a link from Brooks Brothers you can go to that might help. Brooks Brothers: How to tie a tie.

It looks best if it forms an even triangle.
The shirt should not be seen above the knot.
The back sides of the tie should be covered by the collar.
The collar should point down and not to the side, allowing the above.

There are many ways to tie the knot, but as a general rule, the shirt should not show above the tie and it should be even and not to one side. It should form a triangle. While the photo is not about the tie, remember that the knot is in the direct center of the photo and if it looks sloppy, it will make you look sloppy. If you don’t tie the tie often, it is better that I tie it for you. In addition, the shirt sould fit well. If the shirt is a little big or too small, that too will affect how the tie will look.