Today everyone must throw something away, particularly something you've been neglecting to throw away. It could be something minor an literal, like those tomatoes that have been in your fridge just a few months too long, or the stack of newspapers and magazines you need to tie up and take to recycling (recycling counts, too). It could be that box of souvenirs that really has no sentimental value, even after 20 years, or maybe that box of cassette tapes when you haven't had a working cassette player in 10 years.
Or it could be something else, like maybe canceling a subscription that's been a waste of time and money, or making this the first day to stop a bad habit. Or it could be even deeper, like ridding yourself of a negative influence, something (or even someone) that's been weighing you down.
My only two rules are: it can't be regular taking out the trash - it has to be something you've been meaning to get rid of for some time; it can't be too symbolic - you have to actually do something.
For me it will probably be a little of all of the above. But try it. You might be surprised at how good it feels!