K.V.
R. - Hang in there! You are SO NOT alone in this. My son is 3 1/2 and we have had some of the same experiences. I have yet to find one thing that works, as all kids are different. My advice would be to try different things and see which one you are comfortable with. I do give my son a 10 minute and then a 5 minute warning when we have to leave some place and/or he has to take a bath, etc. I learned the hard way that I just have to give the warning and not phrase it as a question where I say ok at the end of the warning. That gave him a choice and he would respond no. Then I was stuck b/c I did ask. I have read that 3 is and age where independence becomes important. They want to have control over things. I have tried giving a choice of only two things - ex. do you want your bath now or in 10 minutes? - He gets to choose but the choice is something I want him to do. He feels control and we have no battle. I also read that at this age the things we think are little things really are big things in their mind. The example I read was that to a 3 year old someone taking a toy is equal to an adult having their car stolen. When I read that it helped me a lot in trying to have more patience with the tantrums. As for public outings, I know it is MUCH easier said than done, but if you can stay calm her reaction may not last as long. My son decided to push my buttons in the grocery store and decided to start yelling when I told him he had to have the seatbelt on in the cart b/c he kept getting out. Well of course people start looking at me like I'm a horrible mom. I surprised myself that day and kept really calm. I quietly whispered in his ear, "wow, look at all these people looking at you. I sure hope the manager doesn't come over and ask us to leave b/c you are being so loud." Then I continued to push the cart. He stopped yelling for a minute and turned around, when he saw all the people looking at him I guess he was embarrassed and so he stopped. Now when we're at a store and he seems to get started, I just say, Oh I hope we don't get asked to leave b/c we're being too loud. It works for now. I also have a girlfriend who uses a sticker chart with her daughter. If she earns a certain number of stickers for completing things during the day that would normally have tantrums associated with them she earns things like extra story time at bed, getting to read books on parents bed instead if own bed that night, bath in parents tub instead of own. Anyway, the gist is she earns extra time not things.
Also, when my son would get going in a full tantrum, we would just put him in his bed and let him cry it out. We would say you aren't in trouble you just need to calm down. We would leave him there for a little while to just get it out. It was the only thing that would work b/c it was as if he was a different person, almost possessed and didn't hear anything we tried to say. Usually it took about 10 - 15 minutes and then he would be settled and we could move on. I always felt like I should've been able to do something, but honestly he just seemed to need to get it out.
Hang in there! You are not alone! Most people will tell you that 3's are harder than 2's :>) Good Luck. I hope you can find something that works for you.