Mårten G Mickos provides advice on starting and building a business based on his experience as an entrepreneur. He discusses topics such as validating ideas, finding the right target market, securing funding from angels and VCs, building commitment in a team, and maintaining belief during challenges. Mickos warns against common mistakes like ideas that are too complicated, not understanding customers, and believing one's own public relations. He emphasizes thoroughly understanding the problem and market before starting, and advises continually experimenting and being prepared to abandon ideas if necessary.