When I pack salad for a brown-bag refrigerated lunch, I don't dress it in the morning (it would be a disgusting slimy mess after a few hours). I don't put the dressing in a separate little container either (which usually leaks; plus, most of the dressing seems to stay in the container when I try to pour it out).
Instead, I pour the right amount of dressing down into one corner of the plastic container I'm packing the salad in. At lunch, I just mix up the salad and dressing and hey presto! a crisp home salad for lunch.
Is this a trick that everybody knows? It was a new thought to Rebecca, too, but maybe the world is made up of rolling epiphany waves and we're just on a different one from the rest of y'all.