In the Conventional Commits article, Mike Perham explains how git commit templating can be used to support commit message consistency.

The key part is the template statement in the ~/.gitconfig:

[commit]
	template = ~/.gitmessage

This references the ~/.gitmessage file which is used as template for every new commit message.
For Conventional Commits, the following can be useful:

# type(subsystem): short description
### Types
# feat: A new feature
# fix: A bug fix
# docs: Documentation only changes
# build: Changes that affect the build system or external dependencies
# ci: Changes to our CI configuration files and scripts
# perf: A code change that improves performance
# refactor: A code change that neither fixes a bug nor adds a feature
# style: Changes that do not affect the meaning of the code
# test: Adding missing tests or correcting existing tests