Do electrical installations by matching the wire colors with the corresponding colors on the outlet. When attaching new wires, loosen the screws on the box, and firmly screw the wires into position. Always turn off the power from the panel box, and confirm using an approved tester.
Plan the wiring layout by deciding on the position of the electrical boxes. If the wires run in a permanently unfinished space, attach the boxes to the studs using nails. Start by fixing wires to the box closest to the breaker box, and run the exit wire from the hole in the direction of the next box. Secure the wires with studs placed 12 inches apart, taking care not to bore through the cable. Run wires through bars that run on the top of the studs, but use the shortest distance to the boxes when performing installation for a closed space.
When fixing lights at the ceiling, make connections for both the ground and live wires. Use junction boxes to add new wiring loops, and always match the voltage capacity of the wires. Allow about 6 inches of slack of wire inside the boxes for easy termination. Leave the wires slack enough near the boxes to eliminate tension if you plan to insulate the wall later.