Steps to a successful release

Add all items to NEWS
Update the contributors list in NEWS ("make git-contrib")
Update the time and place in NEWS
Update version in configure.ac and library numbers in Makefile.am
Check that "make distcheck" works
Tag the release ("make git-tag")
Upload the documentation ("make doc-sync")
Close the github milestone and open a new one (https://github.com/systemd/systemd/milestones)
Send announcement to systemd-devel, with a copy&paste from NEWS
Update IRC topic ("/msg chanserv TOPIC #systemd Version NNN released")