I'm pretty new to selfhosting, but one thing that I know to take seriously is log collection. Since there are a lot of different type of logs (kernel log, application logs, etc) and logs come in many different formats (binary, json, strings) - it's no easy task to collect them centrally and look through them whenever neccessarly.
I've looked at grafana and tried the agent briefly, but it wasn't as easy as I thought (and it might be a too big tool for my needs). So I thought to ask the linuxlemmy community to get some inspiration.
Honestly? I just ignore them. Something seems to be happening to them, as they're not growing infinitely, but no idea why.
It was a bit complicated to set this up, but it took me almost no time at all.