Setup a share drive using your router's storage USB port, I had a TB external which is now my dedicated share drive. I also have FTP enabled and use a DDNS so I can get to my files from anywhere.

Also I discovered something amazing which is I'm able to browse the network drive using my file manager app AND open it with Web Video Caster so I can beam it directly to any Roku or Chromecast. Now I don't need to spend another $100+ on a Pi/components for a dedicated Plex server.