Tara Yantra along with its Mool Mantra is considered very effective medium to fulfil Tara Sadhana.
ॐ ह्रीं स्त्रीं हुं फट्॥
Om Hreem Streem Hum Phat॥
Ashtottara Shatanamavali of Tara
list of Tara Mantras
information on Goddess Tara
10 forms of Shakti