There are as many answers to this question as there are teachers in the world. If you take teaching and your role as a teacher seriously, you probably know how difficult it is to teach anything to anyone!
I firmly believe that there are certain rules we should abide by as teachers.
1. We should know and understand what we want to teach. It seems more than obvious to most but in my school years, I found myself in situations when I felt a teacher didn't know what they were teaching exactly.
2. Once you know what you're going to teach ask yourself the following questions: how many ways do I know to teach it? Which one would be the best for my student(s)? I think that we the teachers rarely search for new ways of teaching something we have been teaching for a long time. We use our tried and tested methods. After all, they always worked in the past, right!
3. Communication is one of the most important things one can master in life. We use it every day in more different situations than we can imagine. How many good communicators do you know though? In all honesty, I know only a few. So my point is that you should communicate as clearly as possible with your student(s). It will save each of you a lot of problems. It is worth mentioning here that as a teacher you should limit your speaking time. Students are not your audience and you are not there to ramble on! It is not a lecture!
4. Students learn by doing so let them! They will be eternally grateful to you for being able to actively discover and analyze different aspects of English and later practice them by communicating them to other students in a group.
5. Games and interactive exercises help students remember better and are also fun.
6. Check if your students understand what you are teaching them. Don't ask them if they understand. Do a short exercise with them. The proof of the pudding is in the eating!
7. Respect your students! Don't humiliate them. It brings me to error correction. You don't need to say which student made what mistake! All you need to do is say that you have heard this and this sentence today in the class. Write it on the board and ask the students to correct it!
There are plenty of books on teaching and I am not going to recommend anyone here. I want to say that experience is the best teacher of all and I strongly encourage you to go out of your comfort zone and teach more difficult students and classes. You will learn much more than you expect. It won't be easy but it should make you a better teacher!
What would you add to this short list? Tell me in the comments below!