Thanks for the article. I would only add that starting freelancers should think about sites like Upwork and Fiverr like they think about training wheels. They’re helpful at the beginning, but for the long term, you’re going to find the most freedom and highest-paying jobs outside of those project aggregate websites.
My experience is that there are a lot more people and businesses who need good writing than there are writers in the market. So freelance sites only create unnecessary competition (which inevitably drives your rates down).
Once you learn how to consistently find clients on your own, you’ve hit the jackpot.