Is it a good idea to compose background music with just instrumentals?

I've always use this one music software and that's MuseScore. I like to compose some BGMs for my films or animations but sometimes, those thoughts always come into mind.

How can I add some sound effects or "music effects" (not sure what it's called to be exact) to the music to make it more dramatic. expressive, etc. I'm not just talking about like adding the ringing sound or any simple stuffs like that. Maybe some bass drops or those modern remix sound effects would work but there's just so much to explore that I'm at lost of what sound effect to look for...