With the mixing it up cubes thing, for us it works like this:
Me - purple, ds - black, dd1 - red, dd2 - orange.
For a week, everyone packs 3 cubes, each containing underwear, a beach outfit, swimwear, something presentable for museums/evenings.
We'd probably have 2-3 checked bags for the 4 of us.
Either way, those 12 cubes get shared across the cases so that if one goes missing, everyone still has a day's worth of stuff.
If we're doing something a bit more adventurous or multi activity, the cubes can be packed accordingly: purple - city & museums, black - jungle trekking, red - home stay camping, orange - beach. Which does require a bit more forward planning & sometimes labelling the cubes with initials in sharpie.
But no, cubes are awesome. Yes, you could achieve the same effect by boldly labelling lots of Bags For Life, tbh, but it's definitely less hassle to just point teens to 'yours are the blue cubes, you packed them...'