To maintain old releases, I just cut a branch before I tag.
Merge to master, short-lived feature branches, and when it's release time, git checkout -b v1.5, git tag -a 1.5.0, and then cherry pick bugfixes onto that branch when it's time for 1.5.1. If you need more time to stabilize for 1.5.0, just add some time & development between cutting the branch and tagging it.
Merge to master, short-lived feature branches, and when it's release time, git checkout -b v1.5, git tag -a 1.5.0, and then cherry pick bugfixes onto that branch when it's time for 1.5.1. If you need more time to stabilize for 1.5.0, just add some time & development between cutting the branch and tagging it.