It is an important skill in real-life communication contexts.
Example
Asking for clarification, rephrasing, and confirming what you think you have understood are all strategies for the negotiation of meaning.
In the classroom
Information gap activities such as jigsaw readings or listenings, group story building, spot the difference and communicative crosswords are examples of activities that give learners the opportunity to develop their communicative competence through negotiation of meaning as they share information.
Further links:
https://www.teachingenglish.org.uk/article/teaching-speaking-unit-6-activities
https://www.teachingenglish.org.uk/article/elt-guide-1-communication-games
https://www.teachingenglish.org.uk/article/motivating-speaking-activities-lower-levels
https://www.teachingenglish.org.uk/article/drilling-2
https://www.teachingenglish.org.uk/article/pairwork-what%E2%80%99s-fridge