Nonverbal communication is crafted from the very beginning of a human’s lifespan. Before a toddler is able to speak verbally there are many non verbal cues that they use in order to communicate. Cute hand gestures and adorable facial expressions allow children to convey what they are trying to say when they have not begun to form the words to speak. They communicate with their tiny bodies and beaming eyes. There are many ways to communicate with a toddler who cannot say exactly what is on their mind. Here are some articles that provide explanations and tips for non verbal communication:

How A Toddler Communicates Non Verbally 

Even though a toddler is not speaking quite yet, they will definitely be sending signals to communicate. This article goes into detail about how a toddler would do just that. It mentions how a toddler might use gestures and facial expressions to show how they are feeling. If a child is shrugging their shoulders they can be communicating that they do not know something or that they are apathetic. A sour face can show that they are upset or that they dislike something. Their tone even without words can express how the child feels.
https://education.gov.gy/web/index.php/parenting-tips/item/1883-nonverbal-communication-in-children#:~:text=One%20of%20the%20most%20common,they%20are%20angry%20or%20upset.

Non Verbal Communication: The Basics 

A toddler’s first way of communicating is non verbal. Although this is a bit obvious, this statement holds major significance because it is the foundation for their social, emotional, and intellectual development. That is why strategic positive and negative reinforcement is important. The article gives examples of both positive and negative types of body language used to non verbally communicate to a child from a hug to shaking a finger at them. The toddler will be able to understand facial expressions just like how their facial expressions will be indicative of how they feel. Tips are provided for how to engage non verbally in a relaxed state with the child. It is educational play time that requires teamwork. 
https://kidsrkids.com/blog/how-non-verbal-communication-forms-the-basis-for-verbal-communication/

Body Language and Tone of Voice 

This article hails from Australia and explains how body language and tone is significant in communicating with a toddler. Bringing as much positivity as possible is what can bring effective communication skills to light. Make sure to smile a lot and share the love! Often, toddler’s will mimic what an adult is doing. While interacting use positive body language and the toddler will emulate that. The article provides tips and examples of why types of body language can be used to fuel the toddler’s communication skills. A slight touch to the toddler’s arm will be communicating to them that you care.

Non verbally, you can teach a toddler personal space. If they are standing close to someone that might feel uncomfortable you can back away with the child and praise them for doing so. If the child is being too noisy and the goal is for them to be quieter, use facial expressions and a hand gesture so the child will know how to hush their tone. The post suggests to get the family involved so that non verbal communication is in sync. The repetition will help the child non verbally respond to adult non verbal communication. The article concludes with additional assistance to children who might require additional needs.
https://raisingchildren.net.au/toddlers/connecting-communicating/communicating/nonverbal-communication

Communication Tips 

This article makes clear at the beginning that non verbal does not necessarily mean that the child has autism and that this point is often confused. The author differentiates toddlers that might be non verbal, preverbal, or have delayed verbal skills. Wherever the child is at in their stage of development, non verbal communication is essential. The toddler’s intelligence level is not based on how old they are and how they are communicating. Therefore, the first tip is to continually keep speaking because they are listening on some level. Speaking simplistically is best. Using a form of sign language can help with a toddler’s non verbal communication. If you want you can use proper sign language! While communicating, staying at a toddler’s eye level can be helpful because they can closely see your facial expressions, your eyes, and your mouth as you speak. Following these tips, the article reminds the reader of the importance of play to keep the toddler engaged in non verbal communication.
https://www.verywellfamily.com/communicating-with-a-nonverbal-child-4177579