All commits should have one of the following prefixes: REL, FIX, ADD, TST, OPS, DOC. For example "ADD: new feature".
Commits should be atomic: one commit - one feature, one commit - one bugfix etc.
When you tag a new release, use the following example:
git tag -m "REL v1.4.0: 157c9c2" v1.4.0
You may get the commit hash from git log. Don't forget to push tags git push origin --tags
When tagging a new release, make sure to increment version in package.json and other files (we have a script for that: ./edit-version-number.sh)
In the commit where you up version you can have the commit message as
"REL vX.X.X: Summary message".