Git: Manage each version of my app?

I am using git and github, and I just finished the 1.0 version of my iOS app. From here, I am wondering how git can best serve me.

I really am just looking for a best practice here, and what others recommend for managing major versions.

Should I create a new branch for each new version, such as for 1.1, 1.5, 2.0, etc? Or should I just keep pushing to the master branch? If so, how do I do this?