Ensure that your learning environment is set up to maximize your ability to manage the class. Students should be clearly visible no matter where you are in the room, and activities should be split up into stations to limit traffic and messes. Supervise your preschool class at all times and nip problems as they start, so you can keep better control of your classroom. Break your schedule up so students have a nice mix of active and inactive work during the day.
An effective method for bringing children's attention back to you is setting up a call and response system. The phrase can be something simple, such as "One, two three, eyes on me!" Students should then reply with "One, two, eyes on you!" Setting up a simple system like this gives you a handy method for refocusing your class in the event that a distraction occurs or the class is becoming especially unruly during an active play period.
You should praise children when they do something good, but be careful about how this praise is doled out. You can use praise to shape good behaviors by only rewarding your students for things that you would like to see continued. For instance, if one of your students puts away his toys after use without being asked, that would be an excellent time to praise him for his actions. Find opportunities throughout the day to praise children for good behavior and they will find ways to get positive attention.
Children must learn that their actions have consequences, but it is important these consequences not be overly cruel or mean. If you have established rules with your class and one child insists on breaking the same rule multiple times, you should start by speaking with the child about his actions. If he continues to deliberately break rules, consider removing some of his privileges. Losing a recess period is usually enough to show a child that his actions are putting him into a negative space rather than a fun one.