When I was still with the Squadron, we used to do some Cam & Concealment. It's not that hard to teach, and it can be used in some sort of night mission, or a Tactical CTF game.
Another thing that you could do, would be what's known as a Psych Hike. What you do is:
Around the time it starts to get REALLY dark, gather all the Cadets around the main fire at the CP, and then tell them to give the staff their watches and flashlights. After that's done, line them up in a single rank, facing a flank, and have them put their right hand on the person's left shoulder (or vice versa), and start walking down a trail, or along the side of a road, and after a while, tap the person in the rear of the column and have him/her stop and proceed anywhere between 10 and 20 feet into the treeline, stop and then stay in that general area (They're free to move around the area they're in, but not allowed to go to another area) Keep doing this to each person until there's none left in the column. (If you've got a large Corps, you could use two ranks and both sides of the road). After a certain time (usually around half an hour or so), start taking them out of the wood. This is best done by just hollering "Out of the woods!", and then lead them back to camp, the same way that they were brought in. When you get back to base camp, have them gather around the fire again, and then ask them a) How long they thought they were in there; and b) What did they do while they were in the woods.
Of course, while doing this exercise, it is critical that NONE OF THE CADETS TALK. It's also best if you don't let them know what's going on until after the hike is done. What this is supposed to do is simulate if you're lost in the woods after some sort of incident (For us, it was always a plane crash, since we were Air Cadets). It's also kind of interesting to hear some of the times that the Cadets say regarding how long they were in there. During one of mine, they were in there for about 45 mins, and the answers ranged from 5 mins to well over an hour.
Obviously, there are some of Cadets that will freak out while in the woods. To prevent incident, let them know that they are allowed to come out of the woods and stand on the side of the road if they really need to. This is really all of the information that you should give them and only tell the person this info when actually putting them in the woods.
This may seem like a rather...dumb idea, but it's actually a very good method for developing situational awareness, and how to react to if you're lost in the woods. My Squadron had many fun times doing these hikes.