I have to say, this thread has got me a bit nervous. My ds is 3 and a bit and I thought I was past the tantrum stage, but some of you seem to be saying yours didn't start til 3.5!
Maybe it's just not all kids? I was out with a friend yesterday & her dd (2.4) had a real tantrum over nothing at all - a full on lying in the road thrashing about & screaming one. I thought her mum was pretty good, she was so calm (although deep down she didn't feel it!), and walked out of sight (but only a few feet away, and we were in a quiet dead-end lane - no vehicular danger!) and waited for her to stop & come of her own accord, which she did. I just thank God I haven't yet had any of those, especially in town, that must be soooo stressful & embarrassing.
I definitely agree with aloha re avoiding unnecessary battles. If dh refuses to put on a coat I say fine, and just bring it with me, and he'll usually put it on after a few minutes. If it's something I really think he has to have on, eg shoes, glasses, I might offer an alternative, eg can ride in pushchair instead, but can't get out without shoes, or no glasses, no story. And there's nearly never an argument or confrontation. I do think it's important to stick to what you've said (and that means thinking through what you've said before you say it!). I recently drove with a friend and her dd out for a day trip & her dd started playing up. 2 of her threats were "if you don't behave I'll ask * to stop the car and I'll get you out and spank your bottom" (We were bombing up the fast lane of the M1 at the time) she then said "if you don't behave we'll turn around and go back" (hmmm, thought i, after 1 hour driving, and only 20 mins from destination, there is NO WAY I am turning round) Never issue a threat if you can't or won't carry it out!
The trigger is also a big factor. I tried a couple of times to grab a couple of things from the shop after playgroup, and each time at least one would have a tantrum and it was so stressful. It took me 2 visits to twig we never go to the shop after playgroup - no matter what!