Most little kids will run everywhere they go. They want to be the first to the play area during free time and they want to be the first at the table for lunch. So, they run. This can create chaos in the classroom and start arguments among the children. The preschoolers need to learn patience and that it doesn't matter who is first or last. Every time a child runs in the classroom, make her return to the place she started and walk. If the class runs, make them all go back until they get it right.
Whenever there is an argument, the first thing many children think of is to hit the child they are in an argument with. Children need to learn how to handle disagreements more constructively. The first rule they must follow when doing this is to keep their hands to themselves. If the students cannot follow these rules, they should be given a timeout in a part of the room where no other children are. You should also make the child tell you how else he could have resolved the problem without hitting.
These are two rules that follow the same logic. The preschoolers on a daily basis think that the only way they can be heard is by shouting. If you have even just a few children in your class, these screaming voices can be a lot to contend with. So, setting up these two rules will help to keep the noise level down. When the children speak, they need to speak in low voices or "inside voices." And if they want to be acknowledged by you the teacher, they must raise their hand. If the students don't follow these rules, you should have them repeat what they said at a lower level, and ignore them if they speak out of turn. If the problem persists, these students can also be given a timeout.
If the preschoolers play, eat or do arts and crafts without cleaning up their own mess, the teacher will have to do it for them. Cleaning up after several children can be a full-time job in itself. Children at a young age need to learn to take responsibility for themselves, and so they should be made to clean up any mess they make. If the student refuses, she will sit, either where the mess was caused, or simply away from everyone else, until it's cleaned up. This way, the child will begin to understand that it is not the teacher's job to clean up after her.