Changing the Lighting and Environment in Your Painting
Give this process a try on your own! If you are struggling with painting from imagination, this can be a great method to help ease you into the process.
Start with a direct study from reference and then see if you can turn that reference into your own original painting.
The only limit here is your creativity. This process give you a lot of control and creative freedom. So let yourself run wild, experiment and see what you can create.