I only teared slightly but didn't need stiches....I was on all fours on the bed. I think that's the best way for a posterior labour (which I had) and in general. Squatting, and anything where gravity assists will lessen the tear. And actually feeling it of course! No drugs or painkillers will assure that you at least feel the push and what you are doing so you are less likely to tear. And a great ob/midwife that can guide your pushing!!!