Discipline - how does it work - does everything require a warning??

[knakered]

Try really hard to do the discipline thing right...but not sure what thr correct response is when they have done something really bad that they know is wrong (mine are 56&8) ie the parenting advice is firm warning then if they do it again - sanction/timeout whatever....but is this appropriate when one hits the other - is rude to me ie doesnt seem sensible "If you break your brothers other arm...you will have 6 miins time out>>>

I try warnings when I can, but the real no no's get a straight time out and then a deprival - eg confiscation of a toy, or removal of a ball from the reward tower (I do 10 balls for a trip to soft play, for example). I think at the ages they are, they are more than old enough to know when they have seriously crossed the line, and that swift discipline follows (reading that back it sounds like I have got it all sorted, but I am stumbling along with the rest of us, really)