I use the timer on the oven for time out on the stairs.
if they have to take turns I use my phone, set the alarm, then "snooze" every 5 mins.
consequences will really emerge from the situation itself, there's no "fits all" solution - of course you can't tell them to have 6 mins time out if you are already running late!
just bear in mind that the worst thing you can do is to feel guilty or stop yourself from doing/avoiding something because what others might think! that's like plague to parenting styles!
also allow yourself to ignore the kids. show them what it feels like to be ignored.
and yes they will rebel, so do swapsies and deals - say it's important that they tidy up their room quickly, because you planned to make some muffins straight after, but there's only so much time, so give them a choice "what do you think boys? 1 hour of tidying and no muffins or 20 mins tidying then fun baking time? hmm?"
see where that's going? also let them have choices that don't matter that much to you (keep that secret though!) and say in return can hey do xyz, so everyone gets what they want.
they will like the responsibility and are much more likely to be fair and keep their side of the deal
you can write mock contracts, just hilarious, they can say what they promise and can choose their own punishment. make them sign it.
we had terrible trouble recently with DS2 (9), just arguing and being bloody slow every morning.
eventually I said " look, in the morning (school run) I will not listen to any complaints or arguing, you just have to do what I say, let me do your tie or wear what I give you etc, it has to be my way, coz there's no time for explanations.
BUT in the afternoon we can discuss anything you want, I will really listen to you, you can tell me what the matter was and we will figure out how we can avoid that problem next time. Deal?"
he was very happy, and though still a bit slow, he is now eager to get ready and doesn't argue back!
yes DH has to be on board and take your side - but you might have to calm down and relax a bit .
sometimes the best solution is to joke a bit, use humour instead of shouting.
you can always try and whisper, amazing how they will concentrate!
and one big positive thought - tell them that families are teams, you are on the same side and every one has to help and work together so you can enjoy each other's company.
do they like football or other sports? maybe DH can explain it it sports terms.
and back to consequences you have to be very specific about what you are requesting!!!
think vague "get dressed" v direct "put your coat on"
give me a specific problem or two that are the most disturbing/urgent - I'll think of solutions!