Making server secure

What can one do to make server more secure? Share your tips so it can be used by others too

There is no one way to “make the server secure”. Any form of security is going to be dependent on the specifics of your threat model and risk tolerance.

The installation guide gives several suggestions that are generally applicable for most cloud-hosted VPSs, including installing fail2ban to prevent SSH brute-force attacks and adding a simple iptables firewall.