I had a lot of success with my first 30-day challenge. It was a 30 submissions challenge (like you, to 30 different pubs). So I'd written around 15 articles ahead of time, which I'd recommend. At the end of the Challenge I had my first month of earning over $400. Many of the articles I published in that first challenge continue to earn well. I learned a ton about my writing abilities, and I met some amazing writers.
My second challenge was a lot harder, because I'd only written around 5 articles in advance.
I love your raw honesty Doran, it's what makes your writing so powerful.