Here are a couple that come to mind:
1) I no longer turn off my phone during take-off and landing. I always suspected this was kind of bogus--the idea that my phone could interfere with the navigational and control systems of the airplane--and then an episode of "Mythbusters" confirmed it. There could be no higher authority than "Mythbusters." I abhor busywork in all its forms, and powering off electronic devices is busywork. Sometimes I toggle the little switch in my iphone settings to airplane mode, and sometimes I don't even do that.
2) I no longer soak beans. Who knows that they want to eat beans a day in advance? I am not gifted with this power of bean planning. So I just cook the crap out of them and it works fine.
And A Rule I Would Never Break:
1) No parking in handicapped parking unless you, yourself, are handicapped. At times I have known people--some of them were even members of my extended family--who gamed the system to get one of those handicapped parking tags without actually being disabled, or took advantage of the fact that they were driving in such a car to park in the handicapped spaces. That is the worst kind of laziness. I don't believe in hell, but probably just living their selfish lives is punishment enough.
Apparently I feel quite strongly about this.
Now, ON THE OTHER HAND, you know those fake cutesy spots at Kroger and other places that are marked "Expectant Mother Parking?" I sometimes interpret that broadly to mean "Mothers of Small Children and Women Who Are Feeling Harried."
And what about you, what rules don't apply to you, little miss?