I knit a hat and it ended up being too small, so I frogged it and am starting over with more co's. The hat that I frogged used up almost all of 1 skien so I know that this hat will use a little more than 1 skien. My question is this...should I knit until the first skien is gone,even though it will be nearing the completion of my hat, and then start using the second skien or should I knit the hat about half way and then switch to the second skien? Or doesn't it really matter that much? :??