Production design is a combination of visual elements like props, costumes and locations that combine to create the overall look of a film.
Before writing your script, think about locations you have access to and whether or not they have the appropriate look for the story.
If your story is supposed to be set on a space-ship, you cannot shoot it in a bedroom.
If your story is set in a big city, you will have to film in locations which either are, or look as if they might be, somewhere urban.
Think about where you can get permission to film and how you can dress or change locations to suit your story.
You may not be able to film in a hospital but if you have access to a similar looking location you might be able make temporary changes to it.
For instance, making signs for wards and medical departments and putting them up in a corridor.
Combining props, costumes and locations creatively can help create a world.
If you wanted to make a corridor in a school, office building or youth centre seem more like one in a hospital, you could add screens and signs.
You could also give characters simple props like medical uniforms and clip boards to help create the impression of a medical environment.
If you are applying any make-up or make-up effects to a character you should experiment with these first.
Taking test footage of different designs will help you ensure that you get the desired look.