Acupuncture can help as well as walking, certain yoga positions, sometimes sex, and also Clary Sage and Jasmine essential oils.
I swear by this. Its sent mW into labor all of my pregnancies and I plan on using it this pregnancy. Get a yoga ball and sit on it and bounce up and down then switch between that and sitting and rotating your hips. I would bounce for an a few hours a day. It sends me into labor everytime. I do it for a few days and it definitely works.