Does your child have low, average, or high sleep needs?
I thought I was doing something wrong for a long time, but finally came to terms with the fact that my son has low sleep needs. Lucky me!
The sleep charts and sleep books don't apply to us. My son sleeps 10-10.5 hours overnight and takes about 3 hours worth of naps during the day (sometimes 2.5). I followed Weissbluth almost to a T, except that we've never eliminated night feedings since my son generally sleeps through the night unless sick. He's 8.5 months and he's been this way for a long time.
I consider low sleep needs something like my son, average sleep needs 12 hours plus naps, high sleep needs sleeping more than 12 hours overnight plus naps.