At school they use a "reward system".   In other words, his good behavior results in him getting a reward.   In his case it's a trip to the treasure chest.

      It's all set up as a "token system", he has a set of "expected behaviors", things he should and shouldn't do, for each that he follows through with for the day he receives a token.   It takes a predetermined amount of tokens to get something out of the treasure chest, so once he saves up enough tokens he trades them in for a prize from the chest.

      It's done so that it isn't too hard to earn the token, you want them to learn to succeed, not fail.   So really good behavior can earn him a prize that same day while breaking a couple rules/expected behaviors will stop him from getting a prize that day, but he will still have the tokens he earned to continue on for the next day.

      You can also use stickers on a chart instead of tokens.   Also, you can take a word the child likes, such as POKEMON... for each undesired response/behavior, cross out a letter.   If by the end of the day there is at least one letter left the child can get a prize, if all the letters have been crossed out then no prize has been earned.

      These are just a few examples of the way the reward system has been used successfully with my son.   I hope that maybe it will help someone else.