I use TortoiseGIT (on Windows) to do my git stuff..
And am using 'NetBeans' to make changes to my local copy of the repository. Upon saving a file it gets uploaded automatically to my pfSense test box. Other than that, its pretty similar. To your workflow..
Git-Sync the latest pfSense master repo to local filesystem.
Make edits / save / test
Commit changes to a new branch
Push branch to my github repo
Submit a PR
The nice thing about NetBeans is that knows the complete 'project' and offers completion of function names and some basic validation of code and variables used..