Use any you want. I’ve been mounting my internal secondary hard drive on /mnt for well over a year now and haven’t had any problems. Previously, I mounted it on ~/Storage
and it also worked fine (though only because I’m the only user in my computer; dual-user systems would result in the other user being unable to access the hard drive).
I’m not technically inclined at all, so the most duct tapey thing I can remember was hacking Gnome to use Nemo as my file browser instead of Gnome’s default file browser once.