My top tips: All sports kit/dance kit/swimming kit is put back into the kit bag (not drawers) once washed. You’ll always be ready.
Fit shaker pegs on the corner of one wall of a child’s room (ours are behind the door) on each one have kits bags - swimming/dance/PE/school bags ready. Label the top of the peg with the day of the week needed.
Get kids to hang their uniform on their bedroom door handle before they go to bed including underwear/tights etc so there is less hunting in the morning.
Put all similar coloured hair bands/ribbons in small sandwich bags into a larger basket/box so you don’t need to hunt around for house/team coloured ribbons when your child remembers it’s sports day/st David’s day/whatever.
Have one box for costumes for world book day/ww2 evacuee day/Greek day/ space day whatever (schools tend to follow the same pattern every year) then put back into the box once used ready for the next child. Same with Easter bonnets 
If your secondary school child has a locker at school, get them to leave the full sports kit and bag in the locker at school (shoes and all) at the start of the term/year and then only bring home what they have worn on PE day in their school bag and wash it that night. Send it back into school next day. Saves the chances of the entire kit for every sport being lost/left on the bus/train etc. Only provide combination locks for school lockers so no keys are needed. If your child has no locker, fit a small padlock onto the double zips on the bag to save anyone ‘borrowing’ kit without being asked. Never drive forgotten kit/lunch back into school - particularly secondary age kids. Let them get a slip/whatever otherwise they’ll never learn to take responsibility.
Have a box for each child’s school letters/permission slips/DofE /whatever and then as soon as it comes home it goes into the box. If it isn’t in the box, it isn’t my problem to look for it 
Music practice is much easier to manage for 30mins before school than persuading when they are tired after school.
Second bedding for each bed folded inside the duvet cover ready for bed change day.
Use colour catchers inside zip laundry bags so they can’t get lost in the machine. Use in every wash - especially where there is makeup or self tan on towels/flannels/bedding
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Put a dose ball of white vinegar (alongside detergents) in with gym kits/school shirts to keep them smelling fresh.
Teach kids how to use the washing machine/dishwasher/iron/make basic meals. Whoever cooks or helps prep gets to sit down after dinner, everyone else clears alway.
Add things you’ve just used up into the Ocado shop as you go along. Get kids to do the same.
One idea I learned this year from MN is to buy in bulk for the year all washing powders/dishwasher/cleaning products etc in January/February when there is no council tax due. Genius.