Positive language is very effective and creates an environment of respect. It's also really challenging as adults because it does not necessarily come naturally when communicating. With some intention and practice, you will be able to see that your child is now listening and following through with your new communication technique.
Be specific
It's important to be really specific in your language when talking with children. When you say "Stop" they may have no idea what you are referring to. Make sure to be specific but also use the least amount of words as possible. You don't want your request for a desired behavior to be misunderstood or ignored because there were too many words used.
Tell them what they can do instead of what they can't do. Make sure your instruction is the desired behavior you would like them to take. This helps children learn and practice the expectation or skill while not feeling punished or disconnected. You are more likely to get a receptive response when providing what you want to see instead of saying "No, don't do that."
Turn your command into a question when possible
Telling your child (or any human for that matter) what to do immediately has their brain put up resistance. When you turn commands into questions, this stirs the creativity part of their brain so they are more likely to cooperate. Instead of "Put your shoes away," you say, "Where do your shoes go when you get home from school?" This doesn't mean you're asking them if they will do something. They are expected to do the desired action of putting their shoes away.
Be willing to teach and practice the behavior/action with your child
Your child may not know how to put his toys away or feel overwhelmed by the task. Make sure you leave time to teach the skill that you are wanting to see. Remember, just like math it takes a few times to learn a new skill so give your child a chance and make sure to be willing to re-teach the skill.
Use a respectful tone of voice and say please when possible
It's important to always have a respectful tone because you are their model and it's important to avoid invoking feelings of shame and/or blame. If you're feeling frustrated that your child is not listening to you, it's time to reflect what could be done differently. Do you need to be closer to give your direction? Are you asking him/her to do something while their back is turned to you? Do they not know how to do what you're asking? Are they having a hard time transitioning and need a timer to help?
It's not always easy to change how we communicate, but you will see that once you implement some of these strategies you will see positive results.