When you like your teachers, it's easier to pay attention to their explanations and improve your marks. When you consider your teachers as friends, you'll certainly have more respect for them. When your teachers consider you to be a friend, they'll feel more open in class and that will probably influence the classroom in a positive way. So a good relationship between students and teachers makes the classroom a very pleasant place. Now here are some tips to develop a friendly relationship with your teachers.
If you have any questions about that subject, ask them. Show them that you're interested in their subjects. That will make them notice you. But never ask questions that you already know the answers to. If your teachers realize that you are not asking real questions, they might think that you're not actually trying to learn, but only trying to make an impression.
You may also talk about non-school topics with your teachers. When you see one of your teachers in the hall, greet him/ and ask if he/she is going to that concert or if he/she has seen that movie. That way you'll show that you consider him/her as a friend. Most teachers are happy to chat with their students. After while, they may start to talk with you about non-school topics.
The rest is totally up to you. If you want to be friends with your teachers, just treat them as friends, but don't forget that no matter how good friends you are, they will still be your teachers and deserve your respect.