100 times a day, my kids ask for something - food, playdough, and help wedging tiny plastic swords into Playmobil Knights' c-shaped hands. I find them, generally, very polite. They may say, "Mom, can you do this for me?" and they may or may not add "the magic word". When the request is granted, I usually hear 'thank you' or some form of it. I remember when Ethan began attending preschool, his teachers often commented on how polite he was!
I never utter the phrase, "what do you say?" I do not request 'the magic word'. I do not make Seany wait with an outstretched hand for a cookie until he says 'please'.
I do say, "Sean, will you please get mommy a diaper" and thank him profusely. I do say, "Mikey, would you please take the trash out for me." I am always sure to thank him. Use please and thank you alot, model it, mean it, and let it sink in.
And if you ask my kids what 'the magic word is?" they are most likey to say "Alohomora!"