Defining not just your customer or client but the customer’s problem and/or need you are trying to address is the first step. Most business entrepreneurs either skip this step or fail to drill down to a specific target market of customers.
Start with your value proposition. What is the compelling reason that made you want to start this business? If the first answer is money, realizing profits will be tough, but if your answer has something to do with a solution to problem or need you have a fight chance of success as long as you are targeting the customers who need your product or service.