Hire yourself out
Definition 1 of 1
Pro Tip 1/3Service Exchange
Emphasizes a temporary trade of your work for payment, not a permanent job position. 
He would hire himself out for garden maintenance during the summer.
Pro Tip 2/3Not Employment
Indicates a non-employee relationship with an individual or company that's more casual. 
As a photographer, Lisa hires herself out for events rather than joining a studio.
Pro Tip 3/3Multiple Clients
Suggests working with different clients rather than being tied to one employer. 
Tom hires himself out as a personal trainer to various gyms around the city.