When our daughter turned 3, we quickly learned that 3 was going to be much harder than the so-called terrible two's ever were! Her affliction: whining. A lot. My husband and I found ourselves scolding her constantly, to the point that we were tired of hearing ourselves. We knew she had tuned us completely out. So...
We came up with a code: Every time she whined, we touched an index finger to the side of our nose. Pretty soon, she was even touching her finger to her nose when other kids were whining at the playground, etc. When her brother came along, we employed the trick and it worked for him, too!