When I was teaching high school there was talk about handing down a teacher dress code that would require men to wear dress shirts and ties (unless they were coaching a sport) while women could continue to wear jersey pant outfits that to me looked like pajamas—a t shirt, usually with some garish design painted on it, and elastic topped warm up pants the same color as the shirt.
I protested the code, but I took a calculated approach. I said that the students would have far more respect for men teachers who are far more professionally dressed than female teachers who look like they have just rolled out of bed. I guess my approach worked to some extent—the male dress code was relaxed to include polo type shirts or basically any shirt that had a collar.
Perfect. I use this type of negotiating tactic often.
I'll voice an opinion in favor of a particular course of action and then I'll start pointing out the negative consequences of it. In a few minutes, others will be offering alternatives which gives me an opening to offer mine. By the end of the meeting, they are convinced that my course of action was their idea, which is fine with me.