Time, consistency, and patience, I think, work better than anything you can find in a book. Even if you're doing everything "right," the years between 18 months and 4 years old can be extremely trying on the parents. If you're firm, calm, and consistent, they do learn more social, and less irritating and explosive, behaviors, but it doesn't happen quickly.
My DD1 is 5 1/2 now. She was IMPOSSIBLE as a three year old. The second half of that year was the worst. She'd fly into a rage at the drop of a hat, and whine and complain all day, and break down in the face of even the tiniest difficulty. She talked nonstop all day, and would throw a fit if asked to do ANYthing that wasn't her idea.
FWIW, she's grown into a reasonably civilized kid who's fun to be with. She's got her moments, of course, but on the whole she's a kid you'd like to hang out with.
That doesn't mean you don't keep searching for what works. But it does mean that you can't conclude that what you're doing isn't working, just because it hasn't worked yet. It's like teaching a baby not to hit-- you have to tell them a thousand times, and stop them from doing it a thousand times, and show them appropriate ways to touch, again a thousand times, and then finally one day, months or years later, all that accumulated repetition and consistency seems to "take."
Also she became more cooperative.
