First check out your settings policies and then think about the procedures you use to get the children to behave!!
eg star chart, verbal praise, stickers, showing work to other adults/parents, setting a good example yourself eg be a good role model, positive body language eg thumbs up, high five, smiling, giving children who behave well choices eg choosing the book for story time, comment on a child who is behaving positively eg "Gemma is sharing the toys nicely", make a group charter with rules set by the children eg "Be kind to each other", use circle/group time to talk about unkind behaviour how it makes us feel etc..
Depending on the age of the children you are working with, we have headteacher stickers where the children show their good work to the headteacher and get a sticker, we have "star of the week assembley" where a child from each class is chosen to be "the star" each week. Children with social and emotional difficulties take part in nurture activities to help them improve their behaviour. If a child is behaving negatively a sad face maybe drawn on the whiteboard, they may be warned that they will miss a minute of their playtime if they don't improve their behaviour. If the children collect enough marbles in the jar, they get a treat at the end of the week.
Hope this helps