I'd start by sorting through those containers and getting rid of everything you don't need. Kids toys that kids have outgrown or don't play with, curtains for houses other than the one you live in, extra pillowcases and blankets, probably some of the seasonal decorations.

When you've done the culling, I'd put up some shelving units (the kind you can assemble yourself) or simply stack the containers up on one another.

i agree with the above poster. You need to cull through that stuff and get rid of a lot of it. If all you are doing is storing it all in containers that fill up the basement, there is no point in that.

Toys are meant to be played with, not stored. If you have no window for the curtains, they need to go. Pillow cases are for pillows.

You put it all in nice neat stacks and it will all just sit there until it is way past any use and you have forgotten what is in there.

Get rid of it! That is really the only solution.

By all indications you are storing it for yourself and not on a temporary basis for someone else, or not just until you move, or some other reason other than you have no room for it in your living space.

If you have that many pillow cases, you have way too many, for your use, and blankets, and toys, and holiday doodads.

You have entered a pathway to uncluttered bliss! Once you clear the clutter you may find pleasure and enjoyment in things that you never knew you had. Clutter weighs us down and obscures so much pleasure in our lives.

Welcome!

Wow, you did good! People are going to be very happy to buy your extras. So much better to use things than leave them moldering in storage.

Most of my small appliances are gone now. They were easy to retrieve and kept clean under cloth bags on a garage shelf but we just stopped needing them.

When you use the seasonal decor declutter it. You may not be using a lot of the things, let somebody else enjoy them. I went from a traditional tree to a flat 'wall tree' so about half of the less interesting ornaments went away.

Now, the next important step is to find out how all of that stuff is getting in to your house and make it stop!

Don't buy anymore stuff that needs to be stored and that you will probably not use or ever really need.

I agree with the encouragement to clear out stuff! 30 is a lot. Do you feel free-er now that so much is gone?

I have a tight storage area in the basement of my apartment building, and I want to build a roll-out unit that lets me stack the bins I have on shelves. (mine are heirlooms for my kids when they move out, or cloth I actually use for sewing, or out-of-season clothes, or painting supplies--so there's not a lot of culling I can do)

I plan to get some plywood and build when is essentially a bookcase with permanent shelves that are spaced JUST far enough apart to hold the storage tub. NO EXTRA HEADROOM! (because then things will get wedged in there for storage. And also, this way I can pull out the one on the bottom of the stack without having to move the others. And I can build up, up without having to worry about whether the tubs on the bottom will hold the weight.
(I have a Kreg pocket hole jig that will make this easy)

There are PVC-pipe things you can make, or buy to hold the bins you decide to keep.
This one's on Amazon, but there are others; google "PVC shelves for storage bins"
http://a.co/d/aIO2WXg

You can probably find a handyman to knock something together using 2x4s (or do it yourself if you're handy).
Here's a set of plans: https://dadand.com/diy-2x4-shelving/

And there are brackets that make it easy and cheap
https://www.strongtie.com/miscellaneousconnectors_woodconnectors/wbsk_k

These are sold at Walmart--you just buy 2x4s and cut them to fit.

https://www.walmart.com/ip/Hopkins-ShelfLink-Shelf-Bracket/22580902?wmlspartner=wlpa&selectedSellerId=1194&adid=22222222227016188078&wl0=&wl1=g&wl2=c&wl3=51754752431&wl4=pla-83162257391&wl5=9004397&wl6=&wl7=&wl8=&wl9=pla&wl10=112550058&wl11=online&wl12=22580902&wl13=&veh=semit/p/wbsk

Those are actually the same pvc things I bought. I bought 2 of them but I seem to need more. I have emptied about 10 containers so I guess I had more than I thought! I have donated plenty of clothes but when calling big brother big sister they said they no longer do pick ups! So I will have to find another place to pick up my donations.

Tally_Sue_nyc, from my experience and also others that have older kids then mine, your kids are not likely to want those "heirlooms". For example my FIL has 2 sets of fine china that no one wants (1 of the 3 someone decided to take). I have a friend that wants to give her 3 sets of china away and no takers (she tried to pass it off even to me). My older siblings kids never wanted their stuff either. What is valuable to you is more than likely not going to be valuable to them. We saved a few pieces of quality furniture for our kids thinking they would want it when they moved out. By and large they took very little. If I had to do over, I would have just given it away when we no longer needed it. Your situation may be different but I'd bet your kids will do what most kids in this day and age do, decline your "heirlooms".

I am in the process of getting rid of the major part of my possessions. Neither of my two grown kids have much desire to have any of it.

My daughter would take it, but they have too much of their own stuff. My son and his wife are not interested in it at all.

I would rather get rid of it myself while I am able to to do so.

Really, they will not want all of that stuff that you have saved or acquired.

I don't want much of any of it anymore, either. For most of it, there is very little resell value to it. There is so much excess of it all and the younger folks have an entirely different lifestyle

mine are heirlooms for my kids when they move out,

"Tally_Sue_nyc, from my experience and also others that have older kids
then mine, your kids are not likely to want those "heirlooms". For
example my FIL has 2 sets of fine china that no one wants"

These are my children's belongings, not mine.
Their homemade Halloween costumes, their artwork, their baby clothes that they wore in their photo that they might want to put their own child in someday. Their awards from junior high, their high school yearbook, their posters...

It's not "family heirlooms" (I don't have any of those)--it's THEIR OWN PERSONAL heirlooms.

About 2/3s the childhood things I saved for my children weren't wanted. They wanted a very few favorite toys, books and some dress up clothes and didn't want old school work and awards, their choice and they need to go through the stuff.

that's fine--they can decide what they want to keep when the time comes.

As you said: Their choice.

Not mine.