Maybe you can soak some paper towels in hot water and wring them out, then place the damp crumpled towels in that plastic container next to the eggs. It should not touch the eggs. If you have a makeshift cover for that plastic tub that would hold humidity better, but I guess the heat from the lamp wouldnt get to them then. I would also have the eggs touching each other. They are prolly starting to generate their own heat now too, and they'd encourage each other when they hear each other pecking the shells(That's been my experience). I wouldnt mist them with cold water because it might chill them, use warm (not hot) water if you want to mist them, but humidity from the paper towels is prolly better. You can even place the damp wet paper towels near (but not touching) the eggs.
