Dear Power Writers,
One of the best ways to increase your writing income is to sell your published pieces as reprints. Reprints often earn more than a first sale, especially if you know how to target them.
Also, there is no limit to the number of times you can sell a reprint. I wrote one article that I sold as a reprint nine times, earning a total of several hundred dollars.
So get out those sold pieces and send them out again. And again. And again.