You might start with an understanding of the industries in the market that you can best serve, and with those segments determine those you can serve best as your Target Market. You can then conduct a Voice of the Customer survey starting by writing a customer questionnaire with open ended questions. The survey is best conducted one on one with customers either in person or on the phone. The results can then be translated into a set of needs that you can solve.

Alternatively, you can go into the market selling your services and learn from your customer interactions. Or conduct an event where customers are present where you can learn from them.

Start-ups frequently use the latter, whereas larger established firms are likely to use the former