Both hands are equally interesting, and there is no reason for looking at only one of them. As a matter of fact, there are some who even read feet - yes, both of them. Considering the way the body is connected, the left hand is linked to the right side of the brain and the right hand to the left side of the brain.
When right-handed the left side of the brain is likely to be dominant. From the handreading perspective, your dominant hand is your public face to the world and makes the active decisions, whilst your passive hand shows more the personal and private self.
New lines general develop on the dominant hand - the one you write with. The other hand is your destiny, not your past life.
The hand you use to write with is your dominant hand. The lines on this hand change through the years due to the electromagnetic images from your brain which know your lifepath. Lines can add on. Once added they do not go away.
The other hand is your destiny hand. It generally remains the same throughout your lifetime.