I use time out and the thing about it is, they do not have to calm down in time out. The point is that they sit there for the whole time which should be 1 min per age. If they do sit there the whole time, then time out worked. Then you go up to them and tell them if they want to get up, they quiet down and THEN you explain why time out was used. When they are in time out, you ignore them till the time is up or they are still getting attention and that is what they want and defeats the purpose. When she will not sit in time out, in her crib she goes with the door shut. She can scream all she wants in her room and I do not let her out until she quiets down. Sometimes she screams herself to sleep, some times she shuts right up. Either way, it is out of the middle of the room where I am not going to let it happen.
The thing about trying to stop a tantrum is really a couple of things. One, kids have emotions like we do, and do not know how to get them out. Trying to stop screaming or tantrum really tells them that their feelings aren't valid when they are. They can get mad and cry and scream to get out frustrations, they just have to learn when and where it is appropriate to do so, away from the other kids, guests and me. TELL them it is ok to go scream in their room, show them how to punch a pillow on their bed and when they are done they can come back and act like a big girl/boy. Two, I have never seen a parent trying to control a tantrum where it did not create more stress than was there to begin with. At 2, reasoning doesn't always work so really you just have 2 people out of control when there needs to be none. Take the kid out of the room where her screaming doesn't get looks, comments or action. I know this may sound harsh but you cannot let a kid control the house and everything in it. And while it is a great idea to take them somewhere else and focus on THEM to calm them down, it just fortifies in their mind that their screaming worked and manipulated you into doing something for them. You just cannot always drop everything to tend to that. I do think distractions are helpful, but do not work for really bad fits.
My 2 1/2 year old is starting with this high pitch whistle scream and I can't handle the noise and it upsets my baby, so I remove her altogether. Shes getting to where a threat of going to her bed, makes her stop. Also, even though his behavior is TOTALLY age appropriate, did it coincide with the bringing home of the new baby? Maybe he is jealous and you could let him help more with his baby brother like getting you diapers, and wipes or throwing them away. I found involving Madeline with taking care of her brother made her a lot less jealous of him and more like posessive like it was HER baby she needed to help with. She even starts singing twinkle twinkle little star to him when he cries now to comfort him. But good luck, I feel your pain...