What I would suggest is that you use Craigslist as a marketing tool in order to get potential buyers to visit one of your other online outlets so that you can have a secure transaction there.
You can also sell video clips.
Consider this a business investment.
And since your hustle is to sell feet pics, ensure that the first thing a new follower sees is feet pics! It would be best if you were your sole marketing agency.
Be sure to keep your feet aesthetically pleasing while producing these pics.
More than likely, you would work for advertising agencies or modeling agencies as a contractual employee.