Secure the stage lighting. Use a ladder to check and make sure that all the light equipment is properly secured. Check the nuts and bolts that hold key pieces together. If necessary, add safety wires that will secure a piece from falling should it become dislodged by foreign objects or natural disasters.
Arrange the lighting. Use a volunteer as a stand-in to figure out where certain lights should be. For example, if a performer is going to be in a specific spot, you can have a spotlight automatically set to be pointing at that spot. Put a small "x" made of masking tape on that spot. Also, insert appropriate gels in some of the lights. The gels are color filters that can highlight a person's costume or accentuate a mood. Make sure to mark which lights have which gels.
Learn the equipment that is working the stage lights. Light boards are varied in their technical specifications. Learn the basics as to which knob is connected to which lights and if your light board is programmable to do things like fade-ins and fade-outs, or even complete blackouts. Once you figure out what the controls are, label them for quicker access.
Practice your lighting according to the script or order of events. Consult with the director on what her lighting cue preferences are. As you build up your cues, make a separate cue list to go along with the script, or write the cues alongside the script in the appropriate places. Ensure that the cues match the labels on the cue board! Run through the cues as many times as possible, especially if you are working a stage light board with programs.