Just to clarify, do you understand that it’s illegal to work in a country without a work Visa? Unless of course, you are making aliyah. Also, most of the time you would have to get a job & the work visa BEFORE entering Israel.
That being said, there are still many people that find jobs without a work visa, but they have to make sure that they don’t get caught & they also have to make sure that they leave the country once every 90 days. Otherwise, if you overextend your tourist visa, the country will not allow you to come back.
Either way, I’ve seen people post fliers around town offering everything from cleaning services, guitar lessons, life-coaching, etc. So maybe you should come up with something unique & flexible like teaching computer classes one-on-one? I’m sure that you can sell the idea of something as simple as teaching typing, if you can show others that it can help them gain a better job.