By following the below-mentioned steps you can make the best use of your GitHub account:-
1. You should always contribute to other projects that are shared in Github only if you know that thing.
2. Always try to create own projects.
3. You should maintain the projects that you work on a regular basis, I mean to say that whenever you work on something you need to keep it in Github so you don't have to have a local copy all the times. So whenever a project is needed just clone it and start working. Sometimes you will have to modify quickly and Github's UI is very friendly so that you can do it easily.
4. Always try to collaborate with other developers and work with them on the same projects.
5. You should always read other people's code and other projects to learn more.
6. In order to save a snippet of a code to share or save for later, you should use Github gists.
7. Whatever the features offered by a version control you should use them.
If you want to learn more about Github, then here is an exhaustive 3 hours long and informative tutorial on Github:
If you are more into reading, then you can have a look at the GitHub tutorial.
And, if you are interested to learn GitHub and want to master it with the industry-oriented case studies (which is necessary for every programmer) you can learn it by taking up the GitHub training course.