Linux

That depends on your usecase.

I have setup servers where I mounted extra drives on /srv/nfs

When/If I switch to Linux I will probably mount my secondary drives to folders like

/home/stoy/videos

/home/stoy/music

/home/stoy/photos

/home/stoy/documents

/home/stoy/games

The ~/games will probably be an LVM since it contains little critical data and may absolutely need to be expanded to span several drives, though I would also be able to reduce the size of it and remove a drive from the LVM if needed.

I'd make a simple conky config to keep track of the drive space used

I'd just keep using the default automount spot for automounting drives.

I used to mount network attached storage in /mnt until I had problems accessing it from a Snap. In searching for a solution it was pointed out that snaps are correct in being sandboxed from these types of folders, and users like myself are making things difficult for ourselves by using those system folders.

They said the best practice would be to mount them in a folder in your home directory. I've switched to doing that and it works great.

IMO you should use LVM2 or one of the high level filesystems that have similar features, and then dynamically create partitions and mount them as needed. E.g. Suddenly need 50G for a new VM image? Make a partition and mount it where you need the space.

/mnt is for anything and everything. /media doesn't even exist on Arch based distros and maybe others.

/[UUID or PART-UUID].[partition number/letter]

Mount them where you need. Not /mnt and not /media. Maybe /var or its subdirectory, or /srv, or /opt depending on what kind of data you want to store on that partition.