Uke grabs one of tori's shoulders, usually the fabric of the jacket at the front of the shoulder.
It is in uke's best interest to keep the elbow down while keeping the arms and shoulders flexible.
Kata-dori is not the goal of the attack, but only the first contact. Uke wants to use it to hold tori down or move them into a position where the attack can be continued, e.g. with a kick, strike or by taking tori down.
Search "Basic Forms" page for videos showing KATA-DORI
