I uses freezer bags, they have the little spot to write on too. Of course, I always forget to DATE it, so I don't remember what batch I made first. Oh well, they eat it up pretty quick, so probably even the bag on the bottom isn't that old.
I like the bags better because I can mush it really thin so it freezes and thaws quickly. And if I want to mix one batch of stuff with another batch, I can break off a chunk instead of using the whole bag.