Can I sign 'jaw' with just one hand?
While you might see it done casually with one hand in fast conversation, the standard and clearest way to sign 'jaw' is by using both hands to trace the jawline symmetrically.
Is this sign related to the sign for 'beard'?
They are located in the same area, but 'beard' typically involves a pulling or grasping motion downward from the chin or sides of the face, whereas 'jaw' simply traces the bone structure.
Do I need to actually touch my face?
You can lightly touch your face with your fingertips as you trace the jawline, or hover just slightly above the skin. Light contact is very common and helps guide the movement.