Get your own screwdriver kit. You should have a variety of sizes (most important are the Phillips screwdrivers -- the average cheap kit should do just fine.) The ones in the lesson kits aren't bad, but it's faster to work on kids' problems if you have your own set of screwdrivers.
Include a pair of needlenose pliers. They're good for getting out stripped screws -- and you can expect a lot of stripped screws in these classes.
A magnetic screwdriver is handy... BUT it also can put the motherboard at risk. The 1's and 0's in computer code are stored magnetically, and putting a magnet too near a chip will erase the programming on that chip. This is not a good idea when you're dealing with robots.
Use the magnets to find dropped screws on the floor.
Have kids put the parts they're not working on back in the bag and in their boxes and keep them there. Only have them do a few screws/nuts/bolts at a time to reduce the possibility of parts getting dropped on the floor.
(additional tips are welcome)
