Should I have a more structured lesson. 20 minutes of warmup, 30 minutes of X, 30 minutes of Y, etc? Or will I learn by just exploring different pieces? It isn't clear to me whether I should be focusing on learning a song and just really getting it down, or learning various techniques.
Part of me thinks that learning a song would be ideal. If I was going to teach someone to program, I would probably give them some basic knowledge, but try to get them to understand that only by implementing a program will they really solve problems. Learning techniques -- in code -- is pointless unless you are actually using them and realizing why they work the way they do in practice. Is guitar the same or is this a flawed analogy?
So should I sit down and write out some lesson plans, or should I just go where my interests lead me?