Here are a few basic sorts of knots that hold a tie.

Simple - Fits shirts with Classic Collars

Single - Looks better on short necks. Most suited on wide and heavy fabric ties. Also known as 'Four in hand' knot

Double - The same sort but is a lot wider to look less narrow.

Windsor - Fits shirts with "French cut" Collars.

Single - Goes with any shirt and with a symmetrical triangular knot, it suits wider ties with lighter fabrics.

Double - Goes best with long necks and with a wide triangular knot, it nicely compliments the perceived length of your neck.

Pratt/Shelby - Best for medium fabrics and medium width ties.