Freelancing — once a description of the work of medieval mercenaries, freelancing no longer requires freelancers to go from kingdom to kingdom, offering their jousting abilities for hire. No, these days, you don’t need a lance. And, despite the popularity of freelancing among writers, artists and designers, you don’t need a pen either. Freelancing includes everything from artists to financial consultants.
If you want to freelance, you’ll need to follow much the same path as someone who wants to learn how to become a consultant. In fact, consulting and freelancing are essentially the same thing. However, "consultant" may sound more imposing and deserving of higher consulting fees. The term you use is up to you.