Did you know you can use a coffee cup for white balance? No, not by photographing the white cup and setting a custom white balance based off of it (though that might work too, actually). I’m talking about using the translucent white disposable coffee lid that’s ubiquitous at every coffee shop everywhere. Simply stuff the lid into your lens shade and it acts like one of those fancy Expodisc white balance tools. It may not be perfect, or quite as precise as the real thing, but it sure is cost effective.