Betweeen the size of the Balthus Knot and the Half-Windsor Knot. The Windsor knot is wide and triangular, designed for wide spread shirt collars. It is not a good knot to use with ties of thick material, but, when well executed, is stately and elegant.
Drape the tie over your neck, with the wide end of the tie on your right. The wide end should hang about a foot or so lower than the narrow end.
Cross the wide end over the narrow end and bring the wide end up and through the inside of the loop around your neck.
Bring the wide end back down, around and behind the narrow end.
Pull the wide end up on your right, then put down through loop and across the narrow end. (Refer Step 4 and 5)
Turn and pass up through the loop around your neck. (Refer Step 6 and 7)
Complete the knot by pushing the wide end down through the front of the knot.
Tighten the knot carefully as you flatten out any wrinkles.
Cross the wide end over the narrow end and bring the wide end up and through the inside of the loop around your neck.
Bring the wide end back down, around and behind the narrow end.
Pull the wide end up on your right, then put down through loop and across the narrow end. 
Turn and pass up through the loop around your neck. 
Complete the knot by pushing the wide end down through the front of the knot.
Draw the knot snugly up to your collar.