Genuine Question About Business Niche

I help people walk through their business workflow and identify repetitive tasks that consume time, money or both and automate exactly that. This works across industries. For example, I recently helped a macro trader automate his analysis. I also helped a founder in Manufacturing automate the good inward record maintenance workflow. I am not really sure how I can niche down. So I can focus on a particular segment rather than targeting anyone who comes my way.

Help me identify how to find the niche? Bonus points if you have a strategy around this concept.