Freelancing is basically a different way to work. Freelancers are self employed and find a work via variety of sources. Clients hire a freelancer to complete a task, project or service for them. Freelancer can work from anywhere but many work from home
          To become a freelancer you must be skilled in computer / internet, must have experience in internet marketing and most of all you must have a passion and goal to become a successful freelancer. Marketing strategies are the techniques. Know your clients and deal with it.

Being a freelancer it needs more time and 

the effort to become expert and successful.