On one of the Rav forums I go on (UK sock knitters) there was a thread about what do you do with your leftovers. Sock yarn blankets came up quite a few times, one of the participants, Sorbus, commented that "I have to keep knitting socks to feed the blanket!" (sorry, no blog to link to).
I know that feeling! The mini square blanket has come to a bit of a halt, but I have a good supply of yarn for that one as each square only needs about 3g.
The larger square blanket, using the barn raising blanket pattern, is more demanding when it comes to yarn. This is partly because I have decided it should all be machine washable yarn, most likely Regia 4ply in various colours as that is my go to washable commercial sock yarn. I thought I had run out of different Regia yarns, but found a few in my stash. There are a few of the creativ ones, they come as a knitted length that you unravel. I opened one this week to make a square as I needed a simple project for knit night.
I have another of these in a different colourway, and two balls that I need to make the socks first, rather than jumping straight in with the "leftovers" project!