I read a great article the other day, but apparently I deleted it. It was about how to organize your stash of yarn. Come on, you can't deny that you have one, but is it well organized so that if you need something you can easily find it?
This article suggested putting all like colours together within a ziploc bag. It was recommended to use the largest bags you can find and put them all in there. So all the greens in one bag, all the purples in another, etc. That way, when you need that colour, it will be easy for you to locate.
If you are someone that likes to keep your scraps and then make something with them, the scraps could easily be sorted into its own bag to be kept for embellishments on other projects, or for a multi-colour scrap blanket or other project.