Welcome to WebmasterWorld Guest from 188.8.131.52
There are a good few older WebmasterWorld discussions about minimising bandwidth usage, here's one
Cutting Bandwidth Needs [webmasterworld.com] (2002).
Welcome to the forums, soniagaur
Don't host videos locally, put them on a third party service. Code will be provided to embed the video on your page.
Scrap any background music.
Look for third party hosting for any downloads.
Then start on the more esoteric ways of shaving bytes off your files.
On a side note, if you are on a linux system with apache, you may want to try to hotlink prevention. This site provides go detail on how to execute this in an .htacess file.
Please tell me more about your host, what your bandwidth limit is, and what you are running on your site, and I will see where I can help.