How many times have girls asked me how I got Lillian to be such a good sleeper? She was an awesome napper: 2 2-hour naps at precisely 10 and 3. Into bed at 8, slept until 7 the next day without a peep. All this by 7 months old. She did this until she was a year old, when she went to day care and all the kids there only took one nap, and the peer pressure was too strong for her. Even now (after some issues in our Tucson house), I tell her to go to bed, and she goes whether or not she's tired, and stays there all night (although her definition of "morning" is getting earlier and earlier as it gets bright at 5:30).
How did I do this? A lot of crying. I have given the speech a few times: "You just need to be strong and consistent. You have to let them cry. It will only take a few nights, and then they'll have it. They might relapse when they get a tooth, but just give them Tylenol and tell them to go back to sleep."
I may have given the speech a few times, and I stand by it, but it sure is exhausting to actually do it, especially when the crying wakes up Lillian, too. Then we're all cranky.