Measure the length of the area where your lights will be hung, using your tape measure.
Use a wire cutter to cut a length of galvanized steel wire about double the length of the area you want to hang lights in. This will account for the looping of the wire when the string is hung.
Secure a lag bolt (with eye hook) on each end of the string location, and anywhere else in between where a bolt can be secured, such as a pergola or gazebo beam or outdoor tent pole. Use a pliers to slightly open the bolt eye.
Thread your steel cable through the holes at the top of each bulb housing.
Hook the steel cable through the lag bolt holes.
Use your pliers to close the holes in the lag bolts, to keep the cable from blowing out of the hole in windy conditions.
Screw 60-watt bulbs into the bulb housings.