I teach theory in context, through games, composition, and the pieces students are playing. When teaching theory, I first allow students to experience the concept through their music. Once they have experienced the concept, they can learn to symbolize and name it through games and composition.
I believe that it is equally important for students to learn to create and write their own music. Even very young students can learn to improvise and make up their own tunes. Theory is solidified when students use it to write their own compositions.
Proper, relaxed technique will allow students to developed into great musicians from early on. Without good technique you cannot play with artistry and subtlety, and you are setting yourself up for pain later in life. From the very first lesson we concentrate on playing with relaxed hands and proper posture.
Not every student I teach is going to be a classical musician. Some will, but for most, my goal is simply to give them the gift of music that will last them a lifetime. I expose students to a variety of genres and styles. We play lots of classical music and themes. We play jazz and lyrical and pop music. We learn to read chord charts and lead sheets. We learn to improvise and play by ear. Wide exposure allows students to find what they love, and when they find something they love, I help them foster that love into something that they can carry with them throughout their lives.