Open Source tree or download it from http://www.sourcetreeapp.com/
Step 1: Turn on Git Flow
Click the Git Flow button in the top bar.
Step 2: Get Flow Settings
If this screen appears it means git flow hasn't been setup yet. Click ok to the default settings.
If a different screen appears you can click cancel.
Step 3: Develop Branch
Now you should have at least two branches: Master and Develop.
Master is the branch all the working code that is ready for a public build should be on
Develop is the branch where all the in development features should go, code here should be working but it is a safety net if some bugs are here before going to Master. If you are doing very small changes commit your code to this branch.
Step 4: Create a New Feature
Normally if you are adding a new feature you will create a branch for that feature.
Click the Git Flow button again then click Start a New Feature.
Step 5: Set Up the Feature Branch
Type in a name for this branch, e.g. add_sound then click Ok.
Step 6: Working on the Feature Branch
Now your feature branch has been created under feature/add_sound. Commit and push your changes as normal to this branch until the feature has been fully implemented.
Step 7: Finish Working on the Branch
Once the feature has been implemented you can click the Git Flow button again and click Finish Current. This will merge the feature branch back into develop.
It's a good idea to keep merging develop into your feature branch regularly to avoid the feature branch straying too much from the develop branch.