Y'know, I am not in the calibre of most of the people who do commission painting on this site. I tired it, and at the begining it was kind fo an ego trip to have someone select you, but then it really turned my hobby into work.
If you NEED money, I reccomend a part time job. If you want your hobby to pay for itself and sort of maintain a buoyancy I reccomend just painting mini's and selling them on eBay. You still get to pick what you paint, and how you paint it. Won't pay as much as commission stuff and for me selling them now barely pays for the cost of the unpainted miniature but there is ZERO stress, zero obligation, and it keeps the hobby as a hobby.
Follow Chris/GenerulPoleaxe's advice, it's wisdom!