One of the problems with reading most conventional parenting books is the promise. The promise that if you do "a" with your child, "b" will happen. If you handle a problem by using the given method, the outcome is predictable: Success. It only follows, then, that if you mess up the method, you've messed up your child. Just tweak the method, discipline more, yell less, spank, don't spank, blah, blah , blah...
The problem with all the focus on method and technique in parenting, in my opinion, is how I come to view my children in the process. Instead of seeing each child as a unique individual made in the image and likeness of God, I come to view my child as a product. When the "product" isn't turning out as promised, I have "failed."
I have come to realize after many years of parenting that there is only one foolproof method: Love. Love. Love.
Didn't our Lord say that "Love never fails?" (see 1Corinthians:13)
I am not saying that no good exists in parenting books. There are many wonderful parents writing helpful and informative books. What I am saying is that method cannot be the guide. Love has to be the guiding principle. Do the loving thing.