As for me, first of all you must to analyze all freelance works on all sites. I am always use service http://primelance.com . It`s a good site for freelancers, coz all top-sites with freelance-works are converted in one. Very useful) Then u can find interesting way in writing for you and start work in freelance.
In which are you think you are the best ? You can choose your that skill as a scope of Income . You can sell your skill as freelance services world wide with best freelance website udyamjob .
If you aware about your core area , you can mention here . we would love to suggest you how to start work with your best skill as a freelancer