Another key component to being successful in shaping or changing a behavior is consistency. All persons involved with a child with challenging behaviors must be on the same page. This helps the child be successful. The first thing to do is fill the child's need. If it is sensory, provide sensory opportunities. If it's a tangible a first /then approach might help delay that need especially when it can result in aggression.
Knowing a child's likes and dislikes are also essential in being able to speak to a child's interests or to avoid things that upset the child.
Collecting data and determining if it is working. A true sign something is working, is when the target behavior increases, before it decreases. The child will push the boundaries put in place. It's important to challenge a child but not push them to a breaking point, depending on the situation. These are just a few ideas about why challenging behaviors occur and one approach to address the behaviors. Any questions blog me.