What is the best way to grow in your business? Make your customers give feedback about your needs and how your business meets those needs.
Even if you are starting now or have been in the business for years, you need to know what products or services your customers want today. You need to know where else they can buy, and what they like and dislike about the products and services you sell. Is there any need you are not satisfying? Do you make it difficult to negotiate with your customers? Are there things that you do that customers like? And what do they hate?
Sometimes your clients can give you this information spontaneously, but usually they will only do it if you ask them to answer a questionnaire. If your business does not operate over the internet, you can mail your customers a form and ask them to respond and send it back to you. When the forms come back, write responses to a database or spreadsheet, and then you can organize responses and identify trends.
If you operate over the internet, the process is much simpler. You can use cheap services like Surveymonkey.com to do your research and collect and analyze the responses of your customers.