I need some basic, simple, no-nonsense advice on how to be firmer with my 3 yr old

[NoteSpelling]

He is turning 4 this month.

He has previously had various medical issues and the whole family is in the habit of indulging him, including his siblings. This does him no favours, I realise. I find it very, very hard to be firm with him though, and I would like to change.

I do 'pick my battles' and I think I only say no when I really have to.

He seems to have only 2 reactions to being asked to do (or not to do) something - either completely ignores me, or mega-extreme furious sobbing tantrum.

He is also very stubborn and will quite calmly go without supper rather than wash his hands if he doesn't want to wash his hands.

He is also being pretty naughty at the moment - deliberately ruining his sister's things / drawing on his curtains.

I always have an excuse for him - first he was sick, then he had lost his best friend, now he has a new baby sister. But I think for his sake I need to step up.

Is he feeling a little put out with having a new baby in the house maybe?

The nearly 4 getting ready to start school is a funny age, we are telling them they are now big, encouraging them to do more for themselves and they want to be big and then have a wobble and revert back to wanting to be a baby again.

I spend a lot of time with my just turned 4 year old sort of cajoling her along, lots of games of race you upstairs to get ready for bed or what animal shall we pretend to be to get up the stairs.

We do alot of counting games "I'll count to ten and you see if you can put your shoes on before I get to ten"

Sometimes telling her NOT to do something in a jokey way works "Don't you dare eat all of your brocolilli" "I bet you can't do that zip up, no way can you" and she then pulls her zip and I fall about in mock shock.

You probably do all of these things I think 4 is a very tricky age full of love and rage!!