I always try to say if you find this project satisfied, please feel free to close and let's leave feedback for each other to grow our profiles, however if you think you will have future needs, we can absolutely leave open. If they don't respond, I try to reach out again within a week or so, especially if I am awaiting a fixed milestone approval. This has worked for me majority of the time. If clients ghost for a couple months, I reach out one more time asking about closing or future needs. If they don't respond another month, I close the projects out myself as job completed, so I don't look overbooked.
