Caitlin isnt hitting out - yet!
She does however do the fall to floor thing, going rigid and limp at the same time which makes it difficult to pick her up. Then the kicking, screaming, wailing starts....
I usually pick her up and move her away from whatever she was doing wrong before the tantrum started. To be honest sometimes that just makes her tantrum in a different part of the room but I do my best to ignore her. More recently I have started removing her (have done it twice) to her cot for 5 min time out. This was after she poured/shook a cup of juice over the floor - which she fully understands is naughty. I told her it made me very sad and I needed to clean it up, repeating how sad mummy was at her behaviour. She did go sheepish and lie quietly in her cot until I came back for her.
Its maybe not the best psychological strategy for parenting, but atm the mummy is sad/hurt route is working the best. She seems to not like the thought of me or daddy looking like we could cry (looking cross is funny but!). Again prob not a strategy that some approve of... but iv started telling Caitlin about 'the man' and that is working alarmingly well eg if she isnt picking her toys up 'Will I tell the man?' or if she is kicking/struggling getting her nappy changed I say ' uh-oh the mans at the window, you show him you are being a good girl'.
There is 2-3 months between Caitlin and Charlie so he may not react the same as Caitlin. I hope you find something that works for you. The only thing is I think tantrums/hitting unfortunately are quite normal at this age and prob will continue no matter what we do - until they are nearer 3. Its horrible but thankfully something that most grow out of!