So this is probably the tiniest thing I could declutter in my whole house, but yesterday I decluttered some needles! Sewing is a hobby of mine, but when I was going through my needles (looking for one type I didn't have, of course) I noticed I had two cards of tapestry needles. I haven't done a tapestry since... 1998? So I filled the remaining slots in the cards with tapestry needles from my needle case so they each held a full 6, in the correct sizes. And then I put them in the charity shop bag. I hope someone will appreciate them.
This freed up enough room in my needle case that I could empty a little plastic dish full of needles into it, which was very satisfying, as the plastic case was cracked and, being round, difficult to store. I also consolidated some open packs of machine needles into single cards.
So even though the -needles- were tiny, I ended up removing about 4 cards and one plastic case from my needle box, which is now much more orderly, and it was very easy to establish that I didn't have what I needed after all! Of course, now I've ordered enough new ones to fill up the space (so I would qualify for free shipping) but at least these ones are relevant to my current hobby and will be used up quickly.