Aaron Lauda has a nice description using the package XY-pic here. There are commands that generate pieces of knots (such as crossings in various orientations), although I prefer just using the \crv "curve" command to make splines.

Aaron Lauda has a nice description using the package XY-pic here (Wayback Machine). There are commands that generate pieces of knots (such as crossings in various orientations), although I prefer just using the \crv "curve" command to make splines.