Tripping; Make sure that all wires are taped down (perhaps with colourful tape) and all tripods, lights and backgrounds are secure or out of the way. Make sure that everything is secure so nothing can fall out of place and hurt someone.
Lights; Make sure that people with epilepsy or other disabilities/illnesses that are affected by the lights are not in the studio when the lights are in use. The darkness makes it hard to notice things like wires on the floor so people who are in the studio need to be more aware of their surroundings. Do not touch the bulbs when they are on, turn them off and wait about ten minutes until you touch the lights or else they can cause severe burns.
Drinks; Keep any liquids away from the studio at all times so there can be no electrical hazards.
Bumps; Make sure lights, wires and other things that hang are out of the way so no one will get hurt from them.