When I fork repos, I often like to keep my personal fork neat and clean, containing only branches that I personally implement.
Given that, I fork and then delete all of the original branches that come from the parent repo (but keep the master branch, since GitHub requires a branch that acts as a main, 'master' branch).
- Fork the branch on GitHub
$ git remote add forkName git@github.com:joshavant/Foobar.git
$ git fetch forkName
$ git branch -r | grep forkName | sed 's/ forkName\///' | grep -v '^[[:space:]]*master[[:space:]]*$' | while read line ; do git push forkName --delete $line ; done