The first part of helping your child/student connect head and heart is to help them technically master their repertoire. If your child is 10 years old, that may mean getting them through Suzuki Book 2 with all musical details in tact. (Of course, with the help of your teacher!) Or, if your student is 14, mastering their repertoire may mean learning a simple Mozart concerto with all three movements memorized.
Scales must be fluid, phrasing smooth, repeats in the music must be solid. Beginnings and endings must be confident. Posture must be natural and supportive of the instrument ergonomically.