The first thing you can look at is the size. Size indicates the Personal Presence of the person. If they are going to draw attention when they walk into the room. Sort of like the difference in being noticed of a bold patterned blouse verses one of medium blue verses a white. Each inherently will be noticed more.
Large Writing indicates the person likes being noticed, stands out in a crowd.
The person may have a broad perspective, makes an impression, is bold, ego driven, action oriented, not given to details, can be egocentric. Medium Writing indicates a person who more fits into the crowd , practical, realistic, balanced, works well with others or by oneself. Very Small Writing indicates a private person who typically stays out of the limelight, is introverted, has good concentration, is precise, low-key, cerebral, and can be selective. The gap in the size, from small writing to large signature, indicates a big difference between how this person feels inside and how they present them self. Often found in the writing of very detail oriented people.