The best way to think of a prop is to see it as a Character, it has to have personality! Perhaps it belongs to a dark environment, you might want to design it with straight and jagged edges, or if it's friendly and requires more soft, less threatening shapes.
This Prop Art Idea generator will help you to design a specific asset with a focus on where and what it will be used for. It will get you thinking how to approach a prop design for different media, e.g A prop for a Mobile game will differ to an FPS game.
Examples of Generated Character Design Briefs & Ideas