Branches are cheap in git. This is how I use branches to release safely and iterate quickly

I commit a fix in a dev branch

$ git commit -v -m 'closes #101'
$ git branch
* dev
  master

I create a branch called dev-master which will be a new branch where I will do the actual merging of 2 branches. The parent of the dev-master branch will be the dev branch.

$ git checkout -b dev-master
Switched to a new branch "dev-master"
$ git branch
  dev
* dev-master
  master

I then merge master

$ git merge master

I change to the master branch and merge dev-master

$ git checkout master
Switched to branch "master"
$ git merge dev-master

Push to origin and clean up

$ git push origin master
$ git branch -d dev-master

If there is a conflict or if I need to back out of the merge I can do all the hard work in the dev-master branch without impacting any other branches.