Lots as per the above.
Definitely bath/shower and uniform including socks/tights set out the night before.
Shoes, coat, bag, snacks ready by the door the night before.
In the morning... get up, go to the toilet, get dressed, make bed straight away, go downstairs. No going back upstairs. Apron on over uniform for breakfast. Set breakfast things out the night before if needed... prevents decision fatigue (yours and theirs) and kitchen traffic.
TOP tip... have a basket downstairs with the following in it... hairbrush, hair bobbles, flannel, inhaler/meds, toothpaste, toothbrush, sunblock. Keep in your downstairs loo or somewhere easily accessible and near a sink. Everything you need is in there.
Second trip to the toilet.
TV/tablet/book (preferably just a book) only when ready and only when a grown up says so.
Practice mustering everyone by the front door just before you go out, make sure that all people, hats, coats, shoes, bags are in place before you open the door, check that no one has their pyjamas on under their uniform or their favourite bedtime toy that they can't sleep without in their pocket.
The aim is to keep them all close and on task at all times. You do what they do as they do it.