Volunteering is real work!

Do not think that volunteer work, because it is unpaid, is without professional value. For hiring managers, organizing a charity event demonstrates your planning and problem-solving skills, and managing a volunteer association's social media accounts demonstrates your marketing skills. A skill is a skill, whether you get paid for it or not!

How do you mention volunteering on a CV?

For recent graduates (no experience): Place the Volunteer Experience section directly after your education, and treat it like real work experience. Write the name of the association, the volunteer title, and the bullet points you have achieved.
For experienced professionals: Place the volunteer section at the end of the CV. This will add a human dimension to your personality and show that you are a positive and active person in society (which are qualities that large companies like to be associated with).

What activities should you not mention?

Avoid mentioning volunteer activities of a partisan, political, or extreme religious nature that may raise controversy or unconscious bias in the CV reader. Focus on development, educational, and relief volunteering.