As Sara mentioned recently, she and I are both dealing with the Terrible Three & a Halfs. A couple of months ago, I was ready to tear my hair out. I too, got the book, Your Three Year Old: Friend or Enemy. It's short, more of a pamphlet, really. However, it was so depressing I couldn't get past the third chapter.
Then, a friend mentioned to me that she'd started a "Big Girl Chart" for her daughter. For every kind, considerate thing she noticed her daughter doing, she gave her a sticker. I loved the idea and immediately made one of my own. Every time my daughter does something the first time I ask her to do it - sticker. Every time I notice her do something nice for her brother or a friend - sticker. Every time she does what she's supposed to without being asked - sticker. I used to have a "sleep chart" but I've now incorporated that into her Big Girl Chart. So, now all of those rewards show up on the big girl chart as well. Every time she earns $100 stickers, she earns a prize. A trip to Target where she can pick out a toy, under $10, which we buy her.
While we still have our moments, things in our house are a lot better these days and I think the Big Girl Chart's had a lot to do with that. Not only is there more incentive there for her to do "the right thing" but it's helped me change my perspective a bit. When a kid's on a bit of a naughty tear, it can be easy to forget or not notice all of the little things they do right. Having the chart's helped me pay more attention to those things. Like the times she waits on the sidewalk for me while I get her brother out of his car seat. It's made me praise her in the moment and also give her a sticker later on. I have to say, it's nice for both of us to look at the chart and watch it fill up and think of all the good, big girl, things she's done and remember that while this age can be trying, it's also filled with a lot of goodness.