If you go to quora and search a question for your niche,suppose 'how can I edit a custom reactjs website myself without coding? Do I need an cms?'
You'll find people searching. Then you can write a impactful answer and lastly you can say I do this type of job here is my fiverr account.
Then its going to be there forever. Depending on the problem you are solving you can get a lot of clients. I got my first client like this and this works if you give a professional solution. Just don't be salesy.