Here's a half hitched aluminum water bottle sleeve, tied the same way I made the paracord pouches/can koozies, half hitching/needle hitching, but with the hitches spaced further apart. I used about 30 feet of paracord to cover the 750ml bottle and another foot or so for the cord lock and cinch cord finished with a Matthew Walker knot.
With the spaced out pattern of half hitches, the sleeve can get disorganized when removed from the bottle for cleaning, but it can be straightened back out after you put it back on.
The green water bottle came from the dollar store, and although it's not as nice as a SIGG, Klean Kanteen, or Nalgene, it didn't leak when I tested it and I'm satisfied with it.
Another blogger recently tied one and you can see it on their blog: Radiocake