When you take paid jobs, slowly build up your rate.
Once you've gained more experience, honed in on your skills, offer higher quality work, and are able to put all your efforts into each individual project, you are ready to raise your rate.
Something to remember- you may lose some work. Getting paid more means you will have to cut out the people who can't afford you and even people who don't recognize your worth. With that being said, now that you have fewer roles you will be able to focus more time on projects that pay you the correct amount.
A rate increase will make you seem more valuable to new clients. They will value your work more because of the amount they have to pay.
Once you know your value don't settle for something lower! If you start settling for lower, you will be unhappy working on that project because of the pay- leading you to not do your best work. Not doing your best work means (to the client) that you are not worth that higher rate.
If you undervalue yourself people will not trust you.