The idea of old stuff day is to actually get rid of your old habits and start new ones. Do you have some retro stuff that you want to photograph before you get rid of it? Well now is the time.
You can make it fun like I have in the example photo. I had a few old cassette tapes lying around, and I remembered the time when the tapes got caught in the machine, and the amount of time I spent rolling the tape back in.
Let us see your old stuff that really you should let go of, but just haven't got around to it yet.