Me too.
My thing is scratch paper. I have enough to last two lifetimes. I use it for grocery lists, to-do lists, phone messages, etc. When one side is filled up, I draw an “X” though it, flip it over, and use the other side.
I got this from my parents. Dad worked in a bank for 40 years. He would bring home leftover deposit slips (remember those?). We’d flip 'em over and write on the back.
Hah! I was just looking for something in the garage this morning and found an old amway vitamin box. Flat plastic green see through box with hinged lid and a divider making it two compartments. Gramps used to swear by Amway vitamins, we had hundreds of these things. I’d forgotten about this one, one side held screws, the other Bobby pins
I just started saving glass jars. I found they are perfect for storing stinky things, like chopped onions, in the fridge. I used to put them in a ziploc and then put the ziploc in a plastic container. It would still stink up my fridge. A glass jar keeps all stinky-ness away!
I love cardboard boxes, especially shoe boxes. They’re great for storage. Heavy-duty boxes that boots, laptops, skates, etc. come in are wonderful. I store my Christmas ornaments in them.
I also have a weakness for the bottom, heavy cardboard portion of the Velveeta box. They fit perfectly in drawers for organizing.
I have a hard time throwing a twist-tie away. I have a Velveeta box (see above!) in a kitchen drawer just for them.
Hillshire lunchmeats come in “reusable” plastic containers. I use them for giving away leftovers. I don’t worry about getting my container back.
I save most plastic, lidded containers. The larger ones work great when painting and you’re walking around doing the corner work or around trim. It can be sealed up for the next day.
My husband loves his empty coffee “cans” - they’re actually plastic. He uses them for ice melt (salt), bungees, paint, who knows what else. He has them all over the garage.
how do you get the top off?
My horse gets her carrots chopped (she has bad teeth from cribbing). I put them in a zippy bag for transport and use the same bag over and over.
Okay, the 13.5 oz conditioner bottle top unscrews (Biolage).
Does that answer your question?
Methinks maybe not.
Let me know, please.
My mother had this issue, and passed it on to us.
I have a shelf filled with used jelly jars. I can’t remember using one, ever.
Last week, at age 52, I THREW AWAY A USED JELLY JAR. Thought long and hard about keeping it, looked at the few dozen I had saved in the lower cabinet, THEN THREW IT AWAY.
It felt sooo wrong. 
The little flat square w/a hole that come on some bread packages are great guitar picks or tiny scrapers. Love 'em.
The pins that are in folded shirts when you buy them are absolutely the best straight pins you can get. I never throw those out.
ETA, I do not, (repeat do not) save metal hangers from the cleaners. Mr.Wrekker has a bin in the barn for scrap metal, that’s where they go.
I use the plastic bags they give you from the grocery store as poop bags for Leet the Wonder DOg[sup]TM[/sup]. Also bread bags. The Lovely and Talented Mrs. Shodan thinks it’s gross to use a bread bag to pick up poop, but I don’t see it.
Regards,
Shodan
Many great ideas here - I do some of them already.
Someone mentioned toothbrushes - when they are done being used for the teeth in my mouth, I use them on the teeth on my bicycle gears! 
I have many items in my bike trip kit that were headed for the trash or recycling. My pillow case is the sack that a set of flannel bed sheets came in - it came with a nice pull string - just stuff my jacket and sweater inside and I have a nice warm pillow for camp. My tool kits are in a couple of plastic containers that came with a shammie towel - they keep things tight and quiet - no rattling.
My add: the heavy rubber bands that hold broccoli or asparagus. I always seem to find a use for them.
I save these, and half-gallons, and take them with me when I go to the local hole-in-the-wall guy who sells bird feeders and birdseed; this is how he sells smaller quantities - in milk jugs, juice jugs, cat litter jugs, etc.
I save mine, and the bags that my newspaper comes in (yes, I still take it) and use them as a sleeve for cleaning up cat barf. When they pile up too high, I take the extras to the animal shelter.
Why would a bread bag be gross? It’s not like it’s going to be reused again.
Those blue and white Amazon padded shipping envelopes.*
I keep a handful of them in the garage to put under my knees/hips when I’m getting down on the concrete floor. If one gets gunky I toss and replace it.
I was actually called out at work for reusing the small plastic bag at my register . I emptied into the big trash bag and put it back at my register. “Next time, throw the whole bag into the big bag and get a new bag!” Okay.
I reuse a lot of items. Talenti gelato plastic containers are wonderful for storing little things.
I reuse the plastic bags that pita comes in as freezer bags. Old toothbrushes are handy for cleaning the garlic press. When I was into woodworking I used to save sawdust. Mixed with white glue it replaced plastic wood as a filler, e.g. for countersunk screw holes. I also had (and still have although I rarely use them) reused jars full of nails.
I didn’t see if anyone else has mentioned this, but we reuse the plastic tubs that lunch meat comes in. They’re great for storing leftovers (as long as you reheat the leftovers in something else – I never put those tubs in the microwave). And if I want to send leftovers home with the kids or grandkids, I don’t mind giving them away because I have a huge stack of them in the cabinet.
I wanted to put what was left of a Suave hair conditioner in the new one, guess I will just have to cut the top off and clean it out
I was looking for a new bottle for my pump shampoo into a squeeze bottle. I like buying the big bottles of hair shower products, seems now they are all pump tops, pump tops are a pain!
I figured out I can use the dish detergent bottle, just transferring it now…not as big a bottle as I thought, only half filled the dish washing liquid bottle.
I reuse the kitty litter jugs. All sorts of uses for the big buckets.
I am a Sam’s Club addict. Buying in bulk gives me a little thrill.
I like the big, honkin’ jugs of Sam’s laundry detergent (dye and fragrance-free!) and Sam’s fabric softener. What I don’t like is the spigot dispenser at the bottom of the jug!
I have saved a number of smaller detergent and softener bottles. When my arthritic thumbs are behaving, I fill up the smaller bottles from the big, honkin’ jugs. Neat, clean and no drbbles down to the floor from those damned spigots!
And to save a few bucks, I dilute the fabric softener about 50/50 with water. I think everybody uses softener too generously. Bath towels can’t absorb water, clothes get tacky.
We had a front loader washing machine that was misbehaving. The repair guy asked a bunch of questions about our laundry habits, and then laid down the law: we were using waaaaay too much detergent! The excessive amount of detergent gums up the pump and motor, and also the clothes won’t rinse clean!
One-quarter cup of detergent per load, MAX. So, I took all the lids from my assortment of saved laundry detergent bottles, and I bought a roll of 1/8" Chartpak black tape. I ran a ring of tape at the 1/4 cup level on each lid. Then I slathered clear nail polish over the tape.
Boy, have I been saving on laundry detergent, now!
~VOW
Me too. It now contains bandages from some other company.
I saved these too. Didn’t have any use in mind for them; just liked them; filled up most of a jar with them. Then I changed what kind of bread I bought. The new kind has twist ties, which I do not like. So now when I open a new loaf of bread, I toss the tie and replace it with a plastic tab from the jar.
The plastic bags that you put produce in at the grocery store. I used to recycle them like everyone else, thinking it was the green way to go. Well, it’s even greener to reuse stuff than recycle. So I rince those off and take them back to the store for more produce. I save the store 3 or 4 of these every week. Not a huge savings, but better than nothing.