One day, I'm hopeful that my daughters and sons will tell their husbands and wives-to-be the secrets that will make their lives easier having me as their mother-in-law (poor things).
1) At family get-togethers, don't walk into the kitchen and ask what you can do. That's sure to result in a confused look as she (that's me) is forced to stop mid-thought and work on a new thought: what you can do to help. She has no idea. She's busy trying to figure out how to quadruple 7/8 cup and wondering if she actually basted that turkey or just thought about it.
Instead, stay nearby. She's sure to give you a job when she thinks of one. And she'll appreciate your help then and only then. (All of this to say, she's highly distractable and interrupting her when she's thinking isn't advised.)
1a) How to know when she is thinking and shouldn't be interrupted: she hasn't made eye contact with you or anybody else in some time. This means she's in the zone. You want to stay out of the zone.
2) Do not quit an argument. Should you get into an argument with her (and you undoubtedly will at some point), be tenacious until understanding is achieved. That is, after all, the whole point of the argument. Quitting a disagreement is the equivalent of saying: You're not worth it. I don't really care if we understand each other or not.
She will love and respect you for your persistence.
Now, you know you have your own rules that are followed (or at least known) by those who know you best. Do tell.