Ask yourself what is it you really want to achieve? What motivates you. What is your underlying passion that gets you excited and energized? This is what you should identify first because that is the essence of your message.
Let me give you a hypothetical example of 3 money coaches who are all very successful in their business - wrote books, created training programs, ran 1:1 coaching, etc. Now, you may think they all had similar passions, similar books and similar messages. Nope, wrong answer. While each of them wanted to see his book published and become a best seller, they had completely different motivations to write their book.
One grew up in poverty and had experienced what the lack of money can do to person's confidence and insecurities. He personally embraced the approach of how to value yourself in order to make the money you want to have in life.
The second coach wrote about how to improve your personal relationships so you cannot have resistance to money. He had worked on pro-bono cases with shopaholic addicts that would consider shopping as their therapy for the problems in life they've had. His approach was to help people transform their relationship with money.
The third coach's book was about building wealth and enjoying freedom. He included methods to differentiate personal from financial freedom, true wealth from financial wealth.
As you can see they all had different motivations to write their book. You should understand your unique values and skills before you craft your message.
Here are the 5 steps to create your unique message
The biggest mistake people do when communicating their unique message is elaborating on "What we do" instead of "What's in it for me". Avoid that mistake. Craft a message that will make your prospects want to know more.