If you want to make more interesting pictures, become a more interesting person.
What you're shooting at doesn't matter, the real question is: 'Does it give you joy?'
A photographer's art is more in his perceptions than his execution. In a painter, I think the perception is only the first step, and then you have a kind of hard road of execution.
If you can capture the element of surprise, you're way ahead of the game.
You have to learn not only from your failures. You must also learn from your successes.
Sometimes as you work, you find that you are learning things about your own perceptions and motivations that are way below you consciousness. If you get lucky, you recognize what you are doing, but all too often we don't find the connection between our work and our own motivations.