We all lead by example. If you preach it, make sure you live it! When you take it upon yourself to share a message or give advice, those who receive it will look for its effectiveness in your life. Unless it has changed you, your message will carry less value in changing them.
As you think of others who need to apply what you are hearing or reading, check to see if the same application fits you. Apply the lessons to your own life first because our faults are the ones we often see in others.