Go check out Chris Voss at The Black Swan Group. He was the lead hostage negotiator for the FBI for 25 years and now teaches negotiation skills. His book, Never Split the Difference, is incredible. He doesn’t address the special difficulties of women noegotiating, but I bet he would. I have negotiated my way onto the last seat on a plane, an afternoon free at a $200/hr palapa in Mexico, and better deals than I ever would have imagined using his techniques.