Patterns often contain flowers or leaves or other shapes - knotwork is also popular, though that requires multiple braids looping over one another as they are laid in place.
This sort of decoration takes up some room on the fabric (as opposed to fine, narrow embroidery or edgings) and is often incorporated onto hemlines and wide edgings.
There are three main types of couching techniques used:
Couching is a technique of holding a lance or spear tucked under the arm and guided to the target with the hand of the same arm. This technique became the norm for the joust but is also depicted in the Bayeux Tapestry.