If sales haven't taken off, it's not the end, in any case, you'll be proud to attach this work to your
portfolio. You've qualitatively for yourself and are not in a hurry to put the made design product aside. For example, it can be reused and developed in a fictional case. If you've made a mistake and drawn another Food Delivery UI kit, like many beginners, you can come up with and describe the process as if this work is done for the customer and how you approached it. Based on this story, you can write on Medium, and scatter cool graphics in Dribble and Instagram. You may get valuable feedback and new subscribers. You should always re-use your own graphics to improve your portfolio and create an audience.
I've mentioned above that I didn't succeed the first time, but six months later I made a turn and started to research more before the second attempt. Research is an important stage before the start and I want to dwell on it. Analysing patterns and popular products deeper, I managed to achieve successful experience in the sales of
Figma design libraries, so I'll talk about the creation of design templates made of components or "design system".