The branch should be named after the major and minor version of the module e.g. for 4.4.0 it would be b4.4 , for 4.5.0 it would be b4.5
If the branch does not exist
create it based upon the release tag, e.g. to create a long lived branch for version 4.4, use git checkout -b b4.4 v4.4.0
change the version of the module to the next patch version, e.g. if the current version is 4.4.0 (non-snapshot as this came from a tag) change it to 4.4.1-SNAPSHOT
Create a pull request for the fix
Make sure you have the most up to date version of the long lived release branch for the targeted version
Create a new branch for the back port based upon the long lived branch for the targeted version, e.g. to back port MODPATRON-59 to version 4.4.x issue the following git checkout -b MODPATRON-59-back-port-to-4-4-0 b4.4
Cherry pick the commits from the pull request for the fix (excluding the merges of master unless they are needed)
Push the branch and issue a pull request against the long lived release branch e.g. for MODPATRON-59-back-port-to-4-4-0 the base branch should b4.4
Check that the changes in this pull request are similar to those made for the original fix (unless there are good reasons where that cannot be the case)