[Gabe]

ALWAYS WEAR COMFORTABLE SAFETY GLASSES.
Seriously, if you enforce this rule for all robot activities (demos, competitions, shop) then you will create an atmosphere of good sense and safety that will be very good for the team. A general rule is that if any robot related action requires the use of your eyes, then wear safety glasses.

Have a complete first aid kit at all times.
All kit items should be in a lidded box or bag. You should be able to open the container and remove the contents with only one hand (as your other hand is probably the one that is injured). Essential items: a bottle of rubbing alcohol, roll of surgical tape, antibiotic ointment (ex. Neosporin), gauze pads, bandaids, scissors. Also, open all the boxes and break all the foil seals before you put stuff away to avoid later struggles.

Be clean and organized.
This is just common sense.

Closed toed shoes.
This is an issue more for seniors who tend to wear sandals and flip flops everywhere. For the programmers and electrical people who argue that they never are exposed to the dangers of mechanical people: have you ever dropped molten solder on your foot? If not, would you like to?