Choose the Show
Knowing which play/musical/drama you are going to see is the first step of making a theater report. Until and unless you have not made up your mind in this regard, there is no point thinking about writing a theater report. Most of the time, your teacher will assign the show for you and it may not always be one that you are interested in, but spending that time to watch and really learn it may just change your view in that perspective.
Attending the show is obviously the most important part of the whole report writing process. You should not be writing your report while watching the show, but instead, should be taking down quick notes whenever you see there being an important aspect that would be helpful towards it. Bring a notebook with you for sure and write about how the setting makes you fell, how well organized the production was, lighting, acting and the overall experience. What do you feel like after watching it? All these questions are important for reading out later.
Reread and Write
When you get home, take some time out to think about how the play made you feel and if there are any other things you would like to add. If you were not alone, ask the person who came along with you the same questions and see what answers they give. Finally, begin writing the report with a mind full of the play and write each paragraph discussing one aspect of it. If the play had a meaning, describe it as well as you can, but now all shows will have a meaning.