I have lots of yarn. This is one box of sock yarn, but there are more boxes (1 for cotton, and 2 smaller ones for 6ply and 4ply):
Mostly I make all kinds of socks out of the sock yarn.
There is a good bit left over when a pair of socks is finished (using 100g sock yarn), so I might make socks that need 2 or 3 different colours.
I still have lots leftovers from the various socks I have knitted.
So there will be some monster socks, anything-goes-socks, that might only have the same colour in heel and toe.
And after this, the yarn that is leftover will have become less again, and it goes into a jar. This is pretty enough in itself and would work for me as a home decoration.
I'm making a sock yarn blanket out of the tiniest little bits. It's just knit stitches, and the yarn is held double. This is a long-term project, I've been doing it for about 3 years (though I haven't done anything for about 2.5 years, but I'm back motivated again to continue).
Sock yarn is great! I can justify buying lots because it will get used up eventually ;) I've been watching the World Cup in the last few weeks and needed something easy to knit without paying attention.