If you want to host your own world and only be running when you're playing, just host a world from within the game. If you want to leave it running even when you're not playing so others can join, you DON'T need steamcmd or the dedicated server tool. Instead:
Create a new world
Create a script to run your world
No need to manually update your server with this method. The updates are handled by Steam.
This method should work in the public branch and the ANR beta, as well as any future beta as long as Klei don't make drastic changes to server setup.
Remember to close your world by typing "c_shutdown()" (without the quotation marks) in both windows, or you might lose some progress or worse. The server doesn't have to be empty.
You can, of course, use any other slot. Just remember to change your script in step accordingly, from Cluster_5 to whichever you want.
There's an issue with the cluster token expiring when trying to host through the batch file after hosting the same world from the game. See below how to fix it.
Similarly, you can hide the server from the Host Game menu by changing the cluster folder name (and your script accordingly). The benefit of having it show up in the game as a hostable world is that it makes it easier to manage mods, rollbacks and bans, however doing so while the world is running will probably have unintended consequences (losing progress or the whole world), so ONLY MANAGE YOUR SERVER WHILE THE SERVER ISN'T RUNNING. The benefits of hiding it are avoiding these accidents and having an extra save slot.
If you want to host several worlds at the same time, you'll have to manually edit the ports in the cluster.ini and server.ini files, as always. You can, however, host a world and at the same time play in a different one hosted by someone else.
It is possible to host a world in a different branch at the same time, but you will need to download the DST Dedicated Server tool and a bit of tweaking. Feel free to ask.
Help! E_INVALID_TOKEN or E_EXPIRED_TOKEN
If this doesn't work for you, please detail your OS, whether you're in the beta, the steps you followed, and what error messages you received.