Start Zathura full-screen / remember window size

There's an undocumented launch option, --mode. The examples given for this were "presentation", and "fullscreen", so just use zathura --mode fullscreen [FILE]. If that gets to be a bother, they don't have a configuration entry for this, for whatever reason, so what I did was add --mode fullscreen to my zathura.desktop file. It's a bit of a bother having to use xdg-open to access all of my PDFs, though.

You could use zathurarc to configure the default window size. From man zathurarc:

window-height
   Defines the window height on startup

   · Value type: Integer

   · Default value: 600

window-width
   Defines the window width on startup

   · Value type: Integer

   · Default value: 800