Review the script beforehand to double-check the props list. Consult with the prop master -- the crew member specially selected to care for the props -- to find the props, and set them across the stage. Remind your crew members where they can find the props for the scene. Consult with the director if you have any concerns about the placement of the props or helpful suggestions on changing their placement.
Run a quick check over the scenery to ensure everything is holding together well. Start your check an hour before the curtain goes up so you have plenty of time to make alterations before the show. Ensure doors open fully and close properly. Make sure the walls are sturdy and unmoving when you pass by them. Ensure platforms are able to hold someone's weight as well. .
Run a diagnostic test on the technical equipment before the show. Test the lights to ensure they all work and create the proper effects. Test the sound equipment by having other crew members stand on the stage and read a few lines of dialogue. Also test that your sound effects all work properly.
Speak to the wardrobe manager about the different outfits for each cast member. Present the clothing to each cast member, and help the cast members suit up if necessary. Cover the cast members in barber tarps to protect their costumes from the stage makeup. If necessary, apply the proper makeup to each crew member -- the stage makeup artist may need to give you a few lessons first.