Basically, find a niche industry (refrigerators, greenhouses, toy cars, whatever), find an audience, think about what they could use, and acquire the skills to give it to them. I used to be an actuary before I did software, I plan on going back to my old companies and contracting myself because I know they have data analytics needs I can meet.

If you want an excellent book on this topic, read "Soft Skills" by John Sonmez. Excellent book for shaping your career.