Yes, you are doing freelance jobs then you always have to communicate with your clients and your communication skill is not so good then you may find very hard to make new clients.. ........ so you have to work on your communication skills mainly.........
Also, be honest, honesty is liked by every clients and they think that they are working with reliable person hence the work quality would be good and it would be delivered at right time.
As a freelancer, some times, you may find that you don't have any work and some times you find that you have lots of work so you have to maintain this thing and you have to complete the project one by one. In case you don't have any work then try to send emails to those clients with them you have worked before saying that you need work, I'm sure you would get work from them and your work would not stop.