Tap power for a new receptacle from an existing receptacle. If doing this may cause the circuit to overload or if there is no conveniently located receptacle, tap power from a junction box in the basement or a nearby light fixture or switch.
If one or more new receptacles supply heavy power users, run cable all the way to the service panel and install a new circuit.
When connecting to a 15-amp circuit, install a standard receptacle and 14-gauge wire. When connecting to a 20-amp circuit, use 12-gauge wire and a special 20-amp receptacle.
About 2 hours to run cable and make connections (not including cutting a pathway for cable and patching walls)
Voltage tester, drill, saw, hammer, fish tape, screwdriver, strippers, long-nose pliers, lineman's pliers, utility knife, stud finder, torpedo level, tape measure, pry bar, perhaps a drywall saw or jigsaw
Stripping and connecting wires to terminals, installing boxes, running cable through walls and ceilings
Lay a drop cloth on the floor below.
New receptacle, cable, remodel box and clamps, wire nuts, electrician's tape, protective nailing plates, cable staples
However you grab power and route cables, make sure the cable is firmly clamped at each end and the ground wires are connected correctly.
Pry up a knockout slug in the old box and twist it out with pliers. (If you can't do this, remove the box and replace it with a remodel box.) Remove the sheathing from the cable, strip the wires, and attach a connector clamp to the cable. Push the cable into the box and fasten the clamp.