I disagree that freelancing can provide as reliable a revenue stream as a "traditional" job--especially when starting out. Be prepared for some ups with a lot of downs, and plan for contingencies when revenue is down.
If you decide to start freelancing, it is important to think about the skills that set you apart, regardless of the area or industry in which you freelance. Think about how your particular skills, expertise, or approach can add value beyond what the client is seeking. Demonstrate a solid, above-average value proposition and your clients will become sources of referrals, helping you build a sustainable business.