To begin writing abstract fiction, first free your mind from the typical rules of storytelling. You could focus on emotions or sensations rather than a clear plot. For instance, describe the feeling of being lost in a color rather than a physical place. Read some existing abstract fiction to get a feel for the style, and then let your imagination run wild.
One way to start writing abstract fiction is to think about things in a non - linear way. Don't plan a beginning, middle, and end in the traditional sense. Instead, jot down fragments of ideas, like a single word that evokes a strong image or a concept that seems out of place. Then, start connecting these fragments in unexpected ways. You might also experiment with different points of view, like writing from the perspective of an inanimate object or a concept like 'gravity'. This will help you break free from the normal constraints of writing and enter the realm of abstract fiction.