Grandtutors (formerly at grandtutors.org, now here, with code here) was a lifestyle business that I launched towards the end of my PhD (around when my PhD funding ended) and ran until the start of covid when it was no longer that viable. It started after I was already teaching/tutoring and realised I could streamline everything besides the actual teaching for others. This business had three layers:
While the tutoring services were mainly aimed at GCSE and A-Levels tutors, the classes (around tech and programming) were aimed at non-technical young professionals wanting to upskill. For these I primarily recruited PhD students at various CS departments as teachers to teach 1 hour classes at various meeting rooms I booked around London. TA work at unis tends to pay below London living wage, and is quite mind-numbing, so my colleagues welcomed this significantly better opportunity.
Eventually, we launched the tech literacy classes for the elderly, which we managed to in part subsidise through the earnings of the programming classes and in part through external support. As these were not very technical, I recruited undergraduates with good soft skills, usually as volunteers.