1. Tap on a shoulder 

We use this body expression to capture a person's attention, that is, we touch his/her shoulder so that the person realizes that we want to talk to him/her. We can use this expression in many situations but the most common is when we are in a group of people and we want to interact with a specific person so we touch his/her shoulder to make him/her realize that we want to talk to him/her. 

2. Thumbs up 

Usually when we see this body expression we can notice the person's approval. In other words, when we receive a thumbs up it means we have done a good job. We can use this body expression in many situations but the most common is when we agree with a person and we want to express that approval. 

3. Clench your fists

This type of expression is used when we show anger or displeasure for some action. We can usually see them when people are arguing and we can use it to denote that we are in a negative state of emotions. It is also a sign of greasiness against a person. 

4. Wave to go away

When we see a person move his hand from one side to the other we can notice that this person is saying goodbye because he has to go somewhere else. This expression is almost always accompanied by the word see you later. We can use it to say goodbye and it can also be used to say hello.

 5. Shake hands 

This expression is my favorite since with our body language we are showing that we are welcoming someone in a friendly way. It can be used in many cases but the most common is when we introduce ourselves to a new person. It can also be used to say goodbye in a friendly way.