I just made a slip-cover for the chain in my chain-and-padlock combo bike lock. The chain is 6' (maybe a little much, I know, but better safe than sorry), and the cover is maybe 4'. I cut it into 2 pieces, with some chain showing in the middle, so I can wrap one end of chain around the front tire and the other end around the back tire and frame, and lock them to the middle of the chain with one padlock.
The fabric was 33 cents, but making it took a few hours. Send me a message if you want instructions.