Mahatma Gandhi used the technique of satyagraha which was based on nonviolence, non cooperation, truth and honesty. 

He also used the religious principle of ahimsa, which essentially meant doing no harm to sentient beings. It was a concept found commonly in Hinduism, Buddhism and Jainism. Turning it into a tool for mass-action he would use it to fight not only for India’s independence but also several societal ills such as untouchability.

For more relevant articles, refer to the following links:

• Mahatma Gandhi’s Early Movement
• Gandhi Irwin Pact
• Salt Satyagraha