Gesture drawing involves rapidly capturing the form and movement of a model in a short time period (2 minutes or less) through loose lines and shapes. It helps train hand-eye coordination and understanding of proportion and form. The process involves determining the line of action through the spine and adding volume around this line to define the major body sections and joint positions. Artists should practice different styles like continuous line, line and circle, or using a thick brush to find their preferred approach for gesture drawing.