I've been self-hosting for a few years. However, now I have a single server hosting all of my things whereas, before, I had multiple old machines physically isolating services. I'm getting ready to host a game server or few (at least one for Tilde) on this machine.

While I'm not a neophyte to Linux, I'm not a guru and definitely not an infosec expert.

Given that, what steps do you take to secure a Linux server, LXCs, and docker containers that are receiving port-forwarded internet traffic?

FWIW, I expect I'll have an LXC running docker containers. I can instead run a VM doing same.

Advice welcome!