I have four, live away from family and have a dh who (used) to be in the forces and would regularly come home and say he was leaving for months 🙄 we've come out the other side now the kids are older and dh has retired from the forces and is in a new job but I suppose it's a different kind of juggling when you have a load of teens.
My biggest obstacle was always meals, the last thing you want to do when knackered is be chopping and peeling. I hated ordering take out as it was so expensive and mostly crap but some nights it would be all I could manage.
I used to make something like a huge lasagne on a Sunday and while prepping that I would chop chicken and veg to go into the slow cooker the next morning (for a curry or casserole style dinner) half the lasagne would be frozen and taken out later in the week. This gave me three meals in one prep session.
I always had frozen mash, frozen micro pouches of vegetables and rice in the freezer for nights it got too much. Some chicken dippers thrown in the air frier who micro rice and veg takes minutes and is at least better than ordering a McDonald's.
I still spend a fortune on pre cut fruit but justify it to myself as the kids all eat it and if we buy a whole pineapple or melon it gets wasted as I could never be bothered to chop them 🙈
Even now I always have a m&s pizza meal deal with sides in the freezer so if I'm late home and the kids are starving and just wanting to order dominos I can get one of the older ones to stick the frozen pizzas in instead.
On top of that I...
Use my tumble drier far more than I need to but it's so convenient.
I order a birthday present from Amazon as soon as the invite is accepted.
I always try and keep some cash/change in the house as there is nothing more soul destroying than having to stop by a bank on your way to school/club as the kids have suddenly remembered they need a pound for cakes or a tenner for a trip.
Having a load of girls I always buy about 20 pairs of tights every time I'm in primark and have them handy for the busy mornings they are screaming they have no tights left for school.
Try and buy all toiletries and cleaning items in bulk to cut down on "popping to the shops"