Example: You have a branch `refactor` that is quite different from `master`. You can't merge all of the
commits, or even every hunk in any single commit or master will break, but you have made a lot of 
improvements there that you would like to bring over to master.

_Note: This will not preserve the original change authors. Only use if necessary, or if you don't mind losing that information, or if you are only merging your own work._

On master:

    > git co -b temp

On temp:

    > git merge --no-commit --no-ff refactor

… which stages everything, so:

    > git reset head

Then begin adding the pieces you want:

    > git add --interactive

*The following is from an actual merge.*

               staged     unstaged path
      1:    unchanged        +1/-1 deploy_settings.py
      2:    unchanged        +4/-3 requirements.txt
      3:    unchanged        +2/-1 settings/defaults.py
      4:    unchanged        +1/-1 settings/production.py.example

    *** Commands ***
      1: status	  2: update	  3: revert	  4: add untracked
      5: patch	  6: diff	  7: quit	  8: help
    What now> 

Choose `p` for patch.

               staged     unstaged path
      1:    unchanged        +1/-1 deploy_settings.py
      2:    unchanged        +4/-3 requirements.txt
      3:    unchanged        +2/-1 settings/defaults.py
      4:    unchanged        +1/-1 settings/production.py.example
    Patch update>> 

Enter the number next to the file you want to process first. You can keep entering numbers until you've selected all the files, or you can do them one at a time. An asterisk will appear next to the files you select.

When you are finished selecting files, press 'enter' without entering a number (or anything) to continue to the next step.

You will see a single diff hunk and it will ask you whether to stage it or not.

    diff --git a/deploy_settings.py b/deploy_settings.py
    index 9b110f4..c5b228e 100644
    --- a/deploy_settings.py
    +++ b/deploy_settings.py
    @@ -4,7 +4,7 @@ This file holds the Fabric deployment settings for this project
     from fabric.state import env
 
     #env.project = 'my_project'   #The name of this project
    -#env.repo_base = 'git@git.oldsite.com:%s.git' % env.project
    +#env.repo_base = 'git@git.newsite.com:%s.git' % env.project

    Stage this hunk [y,n,q,a,d,/,e,?]? 

Enter `y` to stage or `n` to skip. This will go on for every diff hunk in the selected files until you get back to:

    *** Commands ***
      1: status	  2: update	  3: revert	  4: add untracked
      5: patch	  6: diff	  7: quit	  8: help
    What now> 

You can enter `s` to see what you changed

               staged     unstaged path
      1:    unchanged        +1/-1 deploy_settings.py
      2:        +4/-3      nothing requirements.txt
      3:        +2/-1      nothing settings/defaults.py
      4:    unchanged        +1/-1 settings/production.py.example

    *** Commands ***
      1: status	  2: update	  3: revert	  4: add untracked
      5: patch	  6: diff	  7: quit	  8: help
    What now> 

You can quit now, so enter `q`, Then do some status and diff commands to explore the staged vs unstaged changes and make sure it looks like you expected.

Don't forget to `git add` any untracked files as appropriate.

Commit the staged changes:

    > git commit -m "merged selected patches from refactor branch"
    # don't do commit -a here… you only want to commit the staged changes

Revert the unstaged changes
    
    > git checkout .

And finally, merge to master:

    > git checkout master
    > git merge temp
    > git branch -D temp