i started freezing tomato sauce and tomato paste (they go bad quite fast?!), in their original glass container, but was really annoyed by having to get it out of the freezer hours before you need it. Otherwise you won't get it out of the glass, or you have to warm it up...
Now i'm putting the sauce and paste into a ice cube tray, works quite good so far.
already heard about the stock option (and forgot about it), but i wondered: how do you handle sand or other dirt attached to the trimmings?
i've tried to filter with a coffee filter, but its really tedious and takes ages until all stock is filtered.
the double freezing option is very cool. do you concentrate the stock, or add just as little water as possible when cooking the stock?