What are some creative ways to design and display vertical postcards for maximum visual impact?

To design and display vertical postcards for maximum visual impact, consider using unique shapes, colors, and textures. Experiment with different layouts, such as overlapping or staggered arrangements, to create visual interest. Utilize contrasting backgrounds to make the postcards stand out, and incorporate eye-catching typography and graphics. Additionally, try incorporating interactive elements, such as pop-up or 3D effects, to engage viewers.