With my kid I adopted the "Parenting with Love and Logic" approach which suggests that we (parents) pick too many battles with our kids and should instead let them learn first hand the consequences of their choices. So in the case of the coat, if the child refuses to wear one then they get to experience what cold feels like.
Time outs have worked very well for me too. Some behavior is simply unacceptable and ignoring it only teaches them they can repeat it.
Lastly, I think there's a tendency to forget that, with kids, they're basically completely different people every few days/weeks. We've gone through a lot of phases with our son and sometimes the best solution is to simply wait it out. More often than not the behavior changes as his brain changes.
Time outs have worked very well for me too. Some behavior is simply unacceptable and ignoring it only teaches them they can repeat it.
Lastly, I think there's a tendency to forget that, with kids, they're basically completely different people every few days/weeks. We've gone through a lot of phases with our son and sometimes the best solution is to simply wait it out. More often than not the behavior changes as his brain changes.