A great way to configure a Raspberry Pi from scratch is PiBakery. After struggling a while with setting up a VNC server and some other things on a fresh Pi connected only via Ethernet (no display, keyboard, or mouse), finding PiBakery was very helpful.
Here's my configuration:
The long string in the second Run Command step is:
DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get -q -y -o "Dpkg::Options::=--force-confdef" -o "Dpkg::Options::=--force-confold" upgrade