[eguanlao]

For suits, I wear shirts with a variety of spread collars to match the formality of the suit. (Yes, suits vary in formality depending on colour, pattern, weave, and fineness of the fabric.) And with those shirts, I like the Windsor and the half-Windsor knots.

For sport jackets and button-down collared shirts, I tie the less formal four-in-hand. I have used the half-Windsor with Oxford-cloth button-downs (OCBDs) too.

I have also used the Pratt knott for OCBDs if the tie is too long for me. (I'm only 5'5" tall.)