8 keystone habits that can transform your life

Some habits are more important than others - they have the power to transform your life.

Charles Duhigg, author of "The Power of Habit," calls these "keystone habits." They are correlated with other good habits. For example, regular exercise often goes hand-in-hand with better eating habits.

Keystone habits don't create a direct cause-and-effect relationship, but they can spark "chain reactions that help other good habits take hold," Duhigg writes.

Here are eight simple keystone habits that can change your life for the better.