How to free up space after backing all on separate external HD
After backing up my macintosh HD with TM into an external HD what could I do next to free space up on my mac storage now that all of my files, vids and pics are stored in a separate HD? I've tried deleting unnecessary docs and files that I no longer need and googled other ways of freeing up space but nothing has work and storage is still full.
MacBook Pro (Retina, 13-inch, Mid 2014), OS X El Capitan (10.11.5)