All the plastic lids!!

I store them in the big cake carrier - rarely make cakes now

For my freezer batch cooking, I use one size container only and have a stack of boxes with a stack of lids behind them. No problem

For the heavier duty, tupperware type cobtainers in random sizes and shapes. I just bung the whole lot in a drawer, and because their shapes are all distinctive a quick fossick around will usually find the right lid for the box I want to use..

Stack the containers inside each other. I keep one spare in which to stack the lids on their sides.

Gave away/offered 3/4 of mine to other people, in my great declutter.
I just dont use as many as I thought I was.

I prepare food for my sister who is paralysed down one side ,also for a couple of neighbours with serious health issues,sometimes my container cupboard is nearly empty and I have to go collect them …my son usually brings the ones he has back I wash them and pairthem with their lids when they all come back and store them stacked by size/shape in a tall larder unit.
My husband says I should charge deposits for onesreturned worth no lids as the food is all free…..I think/hope he,s joking ….lol

Or batch cook furiously so the boxes, with lids, are in the freezer together.

I keep all the lids in a cotton bag in a big drawer, the tubs are in a cupboard above the drawer.

I use a big 'tupperware' cake box to store the lids and then store the boxes inside one another. I keep them on a swing out shelf in a corner cupboard.

Lakeland sell boxes with matching coloured lids. They are brilliant and I will only buy those in future.

Sadly, I still have all the usual old stuff. I did once pair all the lids and boxes and throw away all the ones that didn't have partners. What I had forgotten was all the boxes used to store various things all over the place in boxes without their lids (vitamins in the kitchen cupboard, perishable flavourings in the fridge, lego on the toy shelves) which will, now, forever remain lidless. Hey ho.

Yes, separately- slip containers, one into the other and lids on top of containers, if you know what I mean. That saves space