K.L.
My son had the same type of issues when he started school. We tried to take things away and have other negative consequences but nothing seemed to work. My Mom (who is a special ed teacher) suggested positive reinforcement instead of negative which worked wonders. We had a chart that mimicked the one they had at school (red, yellow, green). If he got a certain amount of greens in a week on his chart, he was allowed to choose a reward. It was never monetary or toy related but things like a game night where he chose the game, movie night where he chose the movie, his favorite breakfast on the weekend, etc... We also incrementally increased the amount of greens he needed to get his reward. The first couple of weeks it was at least two greens, the next couple of weeks it was at least three greens a week, and then by the end, it was all five days needed to be green to get the reward. We saw almost an immediate improvement in his behavior with this method. I hope this helps!!