For "Sitting Duck", I started with a very rough sketch of the scene to explore the idea. Just a few quick lines to think about placement in the scene.
I wanted to express the feeling of being in a confined space when you're at risk. For me this is most common on train journeys.
I followed this up by a slightly finer sketch and added in a few more details to check the composition.
Auto-immune Diseases are invisible illnesses and others on the train do not know the problems their slight cold could cause. When people are coughing and sneezing around me I feel like I should be zipped up in a hazmat suit.
I wanted the scene to show a passenger, seated in the centre of the image and wearing a protective suit but doing some ordinary train activity, suchas reading a book or using a laptop. All the other passengers would be sleeping.
I wanted the inside light to be artificial, yellow and dim. I started with a quite empty train but added more passengers and luggage in the aisle to close the image in.