Safety
Turn off power to the work area where you are working.
Even when power is off, be sure not to touch the electrical wiring.
Do not wear loose or baggy clothing for obvious reasons.
Wear protective eyewear when lifting ceiling tiles, working in dusty areas, drilling, cutting, or sawing.
Locate fire extinguishers when cutting into a wall or working around electricity.
Ensure that cabling used inside walls, ceilings, attics, and other locations meets all applicable fire codes.
Check with building maintenance, about the type of materials you will encounter.