Depends on which supplements. I like to read books, music and TV reviews so keep those, Travel is usually binned unless I'm about to book a hol, Business I glance through, Money I read quite closely, sport, car, gardening, food and drink usually get binned (after maybe a cursory glance through).
A lot depends on which paper you're talking about.
Pretty much every day with the Guardian I end up throwing away more paper than I keep.
Society, Technology, Sport, Media, Review, I don't read one word of it, I just leave it on the tube.
The weekend is the worst though. Almost puts you off buying a paper.
Why bother with a paper and worrying about getting rid of supplements. Most papers are available on line. I read the Times & Telegraph that way, scrolling down and picking up the headlines that interest me. For a small fee (�25 a year) I get the Times crosswords on line and some of them can be completed on line as well as being printed.
I also don't have to ditch the free DVDs and wall posters that have spread like a rash