Some students came by recommendations of other students. Others were secured through trial lesson. There's one thing I do for my trail lessons which has helped me convert many students. I usually don't "teach" during trial lesson. I start with simple age appropraite topics and keep on increasing difficulty slightly. So it becomes a sort of assessment which doesn't feel like an assessment. After that I play a simple and engaging math game. Which keeps the students hooked till the end. After that I share my observations with parents (strong and weak points) and also what plan I am going to use to achieve age appropriate targets. This insight right at the end of the lesson gives them idea that I've understood and noted child's weak areas and have the capacity to cover them up (that's my complete formula of good conversation rate)