How do I know when a teacher is good?

Finding the right voice teacher for you can be tricky. You may have no idea how to select a teacher or what to expect from the lessons itself. You will find many people convinced of very different approaches. Some classical teachers will tell you that to sing modern styles, you need to learn classic style first. Some modern teachers will tell you that classical approach is a waste of time for modern singers. You will be caught and influenced by the beliefs of your teacher. Many teachers will be a waste of time for you, some will be challenging and teachers of "what not to do", and some will help you to accelerate your success,  but how do I choose my voice teacher?

First thing you need to make is to have clear what do you want from your lessons. Improve your technique, sing higher notes, hold out phrases longer, make bigger sounds, run up and down freely...what are you looking for? Do you make it for fun, or you want to become a professional? Depending on that, your homework will be very different.

Knowing that, you can start looking on the internet, or in your local newspapper.

Tips to keep in mind:

• Avoid teachers that scares you with vocal damage. When someone tells you "if you don't sing this way, you're going to ruin your voice", be sure that this person won't let you explore many things. Check extreme examples of metal singers "screaming" for 30 years (smoking and abusing alcohol), that keep their voices working for a long time, and very well-trained singers that develop nodules. So? Who is right? trust in your intuition, your body gives clear signals when you are overusing it. If you see that your teacher talks frequently about vocal damage...find another teacher soon! Don't let anybody to make a living out of your fears.
• The main value of a teacher is that he can give you exercises that makes a real change in your singing. So, for example, singing perfectly is someway doing what-you-want, being as relaxed as if you were in your sofa watching TV. A good voice teacher, will find your personal tensions, and will give you the exact tool you need to release your voice. That means, that if in 6 months you can feel a clear difference in your voice, then you are in the wrong teacher. 
• School of singing. There is classical approach, an italian, a german, a spanish, speech level singing, belting, screaming...and many more. So, which is the right one? What school is better? Ok, first of all, runaway from teachers complaining about others methods. The teacher itself has more value than the method. There are good teachers and bad teachers in every school of singing. So, forget about labels, any good teacher in any school would do the job for some time. In practice, every student is a different method. Be sure that your teacher is applying his method to your needs!
• Nobody can really teach you anything, but you can learn a lot. This is very important. Don't expect that any teacher will do the job for you. 80% of the job is what you do alone. If you are a bad student, even the best teacher can't do anything to make a real difference in your voice. And, if you are a really good student, you will learn even with a bad teacher. Even without a teacher. A teacher is only someone that helps you to get what you want faster. 
• A good teacher will make you feel better after the lesson. Maybe the most important factor of a good teacher, is to keep you excited about singing work. Even if you don't understand the strange exercise that gives you, it keeps you always conscious of your amazing potential. When you feel good going home, willing to start to practice...it is working.
• If you can't find anything interesting in your area, remember that now a days exists internet, and you really can reach any teacher comfortably from home with Skype or similar software. It can really do the job, find an interesting teacher, take a lesson, tell him/her what you want, show him/her what do you have, and ask him why you don't sing as you want. 
• Money. Just because it is expensive, doesn't mean it's better. Just because it is cheaper doesn't mean that is a good choice. I find it normal, to charge between 30€ to 50€ for about an hour. Between this range, keep in mind that anyone that has made a career as a musician (former bands or productions) will charge you for that "name", but it doesn't mean his is a better teacher. Or maybe, just because he spent a lot in his education, doesn't mean that is a better teacher. Maybe that assure that they are not complete ignorant. But being a teacher is a lot more than "I-have-been-an-almost-famous-star" , or "I-spent-20.000€-in-my-education". Normal range, can have better results in general than something very cheap, or maybe most expensive ranges. It is better to do 2 lessons a month with a good teacher, than 4 a month with a cheap ignorant.
• Feel free to ask me for advice in your personal singing needs and the teacher that will do the job better!