I have studied with many teachers and developed some guidelines for myself about who I choose to learn from.
Here are my guidelines.
1. Know what you want to learn. For example, I took lessons from one teacher for three years because I wanted to learn how to have effective practice of Latin technique on my own time. He had very good practice habits in his own professional dancing and knew how to teach me exercises and ways of approaching my own practice that were very beneficial to me. When I felt I had learned this, and was ready to move on, I found the need to change teachers because I needed a feminine perspective, because my male teacher could only take me so far in certain areas.
2. Know how you learn best and find a teacher that matches your learning style. I have found that there are certain methods of teaching that work for me and others that don't. For example, I don't like a teacher to spend so much time talking during a lesson that we aren't dancing. I need to learn both analytically and muscle memory. Also, some teachers explain things in a way that I can get the concept very quickly and others might take several lessons explaining something that just never seems to make sense to me, but seems to make sense to other dancers who take from them. Each of us have different learning modalities. And also, how you learn can change as you progress as a dancer.
3. Know how you want to be treated. When I was a beginner, I wanted a lot more detailed instruction on how to do things and for the teacher to actually watch me practice what they had taught me until I got it right. Now as an advanced dancer, this approach would annoy me. I want a teacher to trust that once I get the concept they are giving me, I will take it with me, work on it by myself, get it into my muscle memory and if I still don't understand things, I will ask them questions. Also, I like to be treated with a certain amount of respect.
4. Discover what the teacher is good at and hire them to learn those things that they excell at. When I was a beginner, I didn't feel qualified to decide who was the best teacher for me. So I interviewed more advanced students of various teachers, came and watched the teachers teaching in the ballroom to learn about their style and also interviewed a professional I trusted who knew the teachers and could tell me what each one had to offer. As I have become more experienced in dancing and being a student, I find that I can tell very quickly what a teacher is good at and what they are not yet as good at. I can also give the teacher directions on what I want them to focus on, so that I spend most of our lesson learning from them the things they excell at.
5. Know the philosophy of teaching that suits you best. I know that personally, I don't enjoy taking lessons from a teacher that feels there is only one way to do things and that their way is right and everyone else's way is wrong. Since I take lessons from more than one teacher, I appreciate it when a teacher can tell me, "This is the way I do this, but there are others that do it differently and this is why."
6. If you are taking lessons as an amatuer couple, then you need to know what you want to accomplish as a couple and also find a teacher who is good at supporting your partnership and helping you dance well together. I have found that some teachers who are primarily focused on Pro/Am competition, are not the best for coaching couples. For example, they may spend much more of their time focusing on one person and leave the other without as much instruction. I also had one teacher who spent lesson time soliciting my amateur partner to dance pro/am with her and who competed with me for his attention instead of treating our partnership with respect and helping to develop it. We didn't continue taking from this teacher very long, needless to say.
7. Look for someone who is a professional in the way they handle their students. For example, I don't want a teacher to use my lesson time to talk about their personal problems. Nor do I want them crossing the boundaries of teacher/student with romantic overtures. I want them to be on time for their lessons and when they are not, to give me a concession in the price of the lesson for that day, or to make up the time later. I also want a teacher to show up for lessons. I don't like to be stood up. These are just a few of the things I would expect from a professional. Also, I want a teacher to treat all their students with respect, especially if they are dancing pro/am with more than one student. I don't like to see my peers treated poorly or slighted by my teacher, even if they are treating me well.
8. Remember the things you have learned about buying services and interacting with people you hire to do things for you. I found that in the beginning, because I didn't know much about dance, it was easy for me to slip into the role of child when taking lessons. What I mean by this is that I didn't bring with me to the lessons the things I had learned in other non-dance areas of my life to give me discernment. Later, I learned that just because I may not know everything about dance, doesn't mean I don't know some things about what I expect from someone I am paying for a service. Also, I needed to remember that I was the one who was paying for the lessons and not let the teacher intimidate me to the point that I didn't stand up for the things I needed and wanted.
9. If you have found a good teacher, don't just drop them when a problem occurs, communicate to them your needs. Being a student means having a relationship with your teacher. I have found that in some instances, if I communicated my needs to a teacher, or let them know what they were doing that didn't work for me, they were able to listen and make changes in their teaching. Teachers can learn from their students too. If, on the other hand, a teacher is so defensive they will not take constructive criticism or an expression of my needs, then this tells me that our professional relationship may not last very long because of their inability to work through problems and listen to my needs.
10. Treat you teacher with respect. I have found it important to treat my teachers with respect. This means being on time for appointments, not standing them up, giving adequate notice on cancelations of lessons, etc. It also means giving them an opportunity to teach me what they know and not being so defensive myself that I can't accept constructive criticism.
Hope this helps a bit.
Dancing and loving it,
Karen