Taking my first steps, I have branched the KStars repository to gsoc2012-spacetime where I'll update my progress. So, I'll document the process for anyone who may need to ever do this. Of course there are different ways to do this but this is the most convenient way I've found. Hopefully the process should be the same for all KDE projects. Although I've had no problems with these steps, if you find any error, please let me know.
- Get write access to the repository.* You'll need this to push anything to remote. Set up your account and git repository using the tutorials given at http://techbase.kde.org/Contribute/Get_a_Contributor_Account
- Make sure you are on the branch you wish to create a new branch out of. I needed to branch master, so 'git checkout master' does the trick.
- Create a new branch using: 'git branch foo' to create a new branch 'foo' (In my case 'foo' was 'gsoc2012-spacetime')
- Switch to foo: 'git checkout foo'
- Make some changes and commit: ' git commit -am "foo commit information" '
- Now simply 'git push' will push any change in any branch in the local repository. But we don't want that. So, we say 'git config push.default current' which configures git to push the current branch by default every time in the future. (add --global if you want this behavior in all your repositories)
- Rejoice! :)
*Getting contributor access is the step which takes the longest. You need to get in touch with someone in the project who will approve your request and even after approval, it can take days to get access. Patience!