I make good use of plastic take away style containers, there dirt cheap, come with lids and are reasonably strong, any time there could be anything from 2-20 of em with parts in stages of different work in progress. What i really like though is there stackable, so for small assemblies as the next bits done they just get piled up, just makes it effortless to keep track of stuff, there also clear enough you can see through them. Customers do take the piss since the local Chinese also started using exactly the same ones, but I was first!
IMHO stackable and with sealed lids are definite plus features, but you also have to pick a size that suits your parts.
