Learn about the children individually, understanding their needs and personalities. A teacher builds a more positive relationship with a child when she takes an active interest in each individual child, and not just the class as a whole.
Give respect to the child. If the child feels loved and appreciated, he'll give that back to the teacher. This is especially important for disruptive students. A teacher who shows care and concern for the student makes it more likely the child will change his behavior.
Give clear rules and guidelines for the classroom. Let the students know your expectations early on, which avoids later conflicts. If the students feel the teacher is just making up rules as she goes, it becomes harder for a positive relationship to exist between the children and the teacher.
Give the children some control over the classroom. This doesn't mean giving them free rein to do what they want, but instead some choice when appropriate. As well, encourage them to share opinions as long as it is productive to the class. This makes the children more emotionally invested in the class.
Meet with students individually. Holding conferences allows the teacher and children to get to know each other better, as well as address specific concerns. Talking one-on-one makes it easier to build a positive relationship.
Model appropriate behavior to the students. A teacher who acts angry or frustrated in front of the class makes it harder for students to respect the teacher and build a positive relationship. Acting the way you want the students to act makes for a more upbeat and productive environment.