I cover everything in towels and sheets then set up a mattress next to my bed (all of which have waterproof sheets on at all times for this very reason) for sick child to sleep on.
I have multiple bowls and buckets so a clean dry one can be got each time and yucky ones in the bath having a long bleach soak.
Kitchen towel, spray, and dedicated bin at the ready and I sleep right next to them (but on my bed) so that at the merest hint of a sigh I am awake and hovering under them with a bowl. It's worth the lack of sleep.
If they complain of tummy ache the next day then don't be tempted to give calpol. Every time I have given some it makes them puke again. Every time. I think it irritates the stomach in its very sensitive state.
If you have enough toilets in your house have one dedicated to the sick child and all cleanup.
And water cups they have used get a through wash in the sicky bathroom/get put straight into dishwasher without hanging around in the kitchen.
If you have more than one child put a baby monitor in the hasn't-caught-it-yet child's bedroom so that if you hear any strange noises in the night you can run in and catch it. Keep a bowl in there too and remove all soft toys and rugs. Put a towel down there too. I had a completely mess free norovirus with a 2 year old this way - heard a little groan, sprinted, caught it, transferred to my room and successfully caught everything thereafter.
It's awful but it will pass. And you won't necessarily catch it either. I caught 'it' but just felt vaguely sicky for a day, much to my relief.
And you can rest easy once it's done - you're all immune for a while, yay!