Here's one I just figured out. Everyone knows you can clip your Arc AAA to a hat brim with the pocket clip to use as a headlamp. But maybe you don't have a hat with you. It turns out that simply clipping the AAA to the inside of your T-shirt collar, then flipping it so it points forward and downward, works pretty well for lighting close-up stuff. Obviously it wouldn't be too good if you're trying to carry something that reaches above chest level. You do have to stand slightly carefully, not great if you're running around, but not a big deal if you're in one place. Note you can still do this if the light is on a neck lanyard. That's probably a good idea in case the clip comes loose from the shirt and the light falls down, though I don't know how likely that is.
You can do something similar with a shirt pocket if you're wearing a shirt that has a pocket.
You can do something similar with a shirt pocket if you're wearing a shirt that has a pocket.