Our ancient texts mention about ten Mahavidya who are worshipped to seek all sorts of powers. Mahavidya worship is known as Sadhana in which worshipper concentrate on a single Goddess to please and to seek Her blessings. In any Sadhana, Yantra and Mantra are considered very effective mediums through which worshippers can reach his target and fulfil his motive to perform it.
In Hinduism, specific Yantra and Mantra are assigned to each deity and those are used as medium to reach the deity to fulfill the motive. Each Goddess along with her Yantra is worshipped through fixed procedure, steps and rituals.