R.T.
I always made my boys sit in front of me on the floor for their time outs. This lets them think about the situation and you don't forget how long they have been in time out. With other children this is easy to do.
I stay with my child and ask the others to go play in another room because it is between me and their brother. This creates a free space for you and your child.
Then we talk: I ask why they are in time out and what we could do next time. This can be trying but it works and instead of anger it creates communication with you and your child. But remember small children forget~ So be consistent!
For tantrums I used a small spray bottle, especially when they screamed. I only had to spray once~!
Use the spray not the stream and stand back from them so they are caught by the misting. This gets their attention immediately and changes focus.
Have a small towel handy~!
Then communicate about the situation~! They may cry but they won't be screaming for long. They will be wondering why you did that and you will be saying why are you acting this way~!
This worked well for my son who seemed to have anger issues at times. I did not use it all the time so when I did it was a shock and a "why did you do that cry". The focus changed and we were able to communicate without anger.
It's very rare now that we experience a tantrum.
I have used this on my grandson as well, and he always says after he has calmed down "Talk gama, talk now" This open communication has created a bond as well, because he knows that we will communicate with sharing and affection.
Good luck to you~!