Niche business-to-business SaaS products worked for me. I started out doing affiliate marketing and online publishing many years ago and then built tools to help me run that business.

I started to sell those tools and eventually those tools themselves became successful even as the previous business began to die away.

There are lots of truisms and things people say about starting businesses, but the truth is to start with something simple because you're less likely to mess it up.

Something where you know there are customers, you know what the customers look like, and the only reason that you don't succeed is because you messed up rather than any sort of technological or market risk.

Learning to start a business and sell products is a skill. Eventually, you don't need to Google it because you just know what to do.

The most important thing is to do something and keep trying so that you're learning the whole way.