From 36 weeks I regularly:

1. Bounced on a fit ball
2. Did the yoga 'taylor' pose
3. Drank raspberry leaf tea (I DD this from 32 weeks)
4. Rocked my pelvis forwards/backwards and side to side while on the fit ball for 30+ min

But mainly I tried to remember UFO - upright, forward and open

I'm not sure if anything really helps as your body is ready when it is ready and no sooner. However, when I was in labour I did use the Taylor pose while in the bath and went from 8-12 min contractions to fully dilated and ready to push within 25 minutes!!!