One way to do this would be to

1. Create a folder called /shared;


2. Create a group with any name, such
   as mediamembers, and add all the users to it. Alternatively, you can
   allow everyone access);


3. Set yourself as owner, and group as mediamembers (sudo chown -R
   yourname:mediamembers /shared; alternatively, just set the
   permissions for /shared to whatever you want for group and the rest
   of the world;


4. Create subdirectories for video, music, pictures, and move the files there from your home
   directory;


5. Create symbolic links to these directories in you home directory's
   subdirectories;


6. In the future, follow the symbolic link to the shared directory to save files.

You could even mount the directory, and in the future, if your media collection got too big, you could put it on a separate disk and mount that in the same place with no changes for the users.

I have mine on a separate partition to solve a different problem, which is to easily access these file when I install a new distro for testing, etc. I just mount the shared partition, and have everything there.