How do I know my intentions are sincere?

Istanbul is loud in the evenings, vendors still shouting as the ferry cuts across the Bosphorus and my phone pings with messages about upcoming talks and a new story series. I tell stories because they make me feel alive, and because people tell me they were moved. But sometimes on a crowded bus after maghrib I catch myself composing lines for likes, not prayer. How do I tell when what I do is truly for Allah and not for applause? Are there small signs or simple practices that have helped you notice the difference in your own life?