PyPi

Preparation:

increment version in setup.py
add new changelog section in CHANGES.rst
commit/push all changes

Commands for releasing on pypi.org (requires twine >= 1.8.0):

find -name "*~" -delete
rm dist/*
./venv/bin/python setup.py clean
./venv/bin/python setup.py sdist
./venv/bin/twine upload dist/*

Github

Steps:

start new release (version: vX.Y.Z)
enter release notes, i.e., significant changes since last release
upload kodi-nfo-generator-X.Y.Z.tar.gz previously generated with setup.py
publish