I've only ever done this with a child to take care of, and I've done it by simply working every possible moment I could, and being organised and focused with my time. However being able to provide for her, made that worthwhile. I started my own business when she was still only at school half days, and we talked about work, and why I needed to work, and that work was where money came from. The money to eat, have a home, and do nice things together.
I count myself lucky that I get to do things I enjoy. However it is amazing what can be achieved with hard work and focus, and a purpose.