Knowing When To Back Off

Knowing when to back off is the prime skill of the patient piano teacher. You should back off as soon as you sense serious resistance from the child. I present a skill and if it is easy to them, I continue.
If they have difficulty, I note what precursor skill they lack and make a note to teach that first before I try the task again. Another way to say it is that aggression never works. And guilt never, ever works. The only thing that really works is patience, lots of it.
Piano Is Easy
A Kid Is Not A Horse, But...
You can lead a horse to water, but you can’t make it drink. Assuming your student is a little more intelligent than a horse, you can also convince the “horse” that water is cool, refreshing and good for you. You can also make a game out of drinking the water yourself. Enough demonstration and you will have a kid eager to try a drink of that water.
You have to watch the child every second to see their micro-reactions to things. Also note what activity they have just left, if possible. Are they physically tired, or were they playing a computer game and want to get back to it as soon as possible?
Swing With Their Mood
Making them feel guilty for not being in the mood for piano is useless. Better to acknowledge their mood and tell stories of how you lose the mood all the time. Just talking a moment can change the mood and let them decide perhaps to play. Take what you can get and make good use of it. Here’s a diagnostic test.
Start a supremely easy activity, such as playing a new favorite song. If the child really seems to resist it, then it is time for less structure.
Back Off Activities
In such a case I immediately switch to game mode, and start playing chord games. Almost all kids see this as a relief from the tedium of serious thought. It's a lot like playing with blocks or Legos. If you are a good player, you can take the time to simply play a great piano piece, not expecting them to learn it.
But share the beauty of the work with them. If you’re not a good player, play a CD. Sometimes we play finger wiggling games, a seemingly silly activity that actually logs more finger muscle development time than most piano practice sessions.
Off The Beaten Piano Lesson Track
Kids love the unconventional approach, sensing that we are off the beaten track. As long as the activity strengthens their interest and skill in some way, it is a valuable digression. There are times when kids are simply too tired or disinterested for a real piano lesson to happen. In such cases, go with the flow.
I play a game called ATOMIC PIANO LESSON which is designed to defuse such apathy. Here's how it goes: I usually sense the child's mood as soon as I enter the room. If I see an exhausted or distraught child, I tell them to sit on the sofa. I say, "We're going to have an Atomic Piano Lesson." They say, "What's that?" usually delighted that they can just flop on the sofa after a hard day at school.
I ask if their arms will stretch to the piano from the sofa. They laugh. They try. Ask silly questions, like, "Where is Middle C?" and allow them to lazily point it out from the sofa. This continues for perhaps five minutes, after which the child feels a little rested, certainly not intimidated.
I play a song or two as if they were not in the room. And guess what happens? Every time, the child will get up off that sofa and come to the piano. If I had insisted on starting the lesson as usual, it would have been like pulling teeth, full of resistance and resentment. Because I backed off and let them find their way to the piano, we actually got some work done in a pleasant atmosphere.