Do you have a certain product your designs work best with?
Does it maybe make sense to produce seasonal designs in a timely way?
With these evaluations in mind, you can fine-tune your portfolio. What also helps a great deal is a consistent social media presence and good-natured self-marketing. So best have a look into our guidelines for inspiration.
It's also not a bad idea to look at other creator shops, design homepages and just generally have your eyes open to what's floating around in the wall art and interior scene. Maybe you see recurring, trending aesthetics you get inspired by but there is no one-fits-all all rule of course.