Food storage containers for the pantry

I store most of my dry goods in plastic or glass containers. One thing I make sure to do is put the new on the bottom. I empty out remaining goods, put the new in and top off with the older ingredients. If any is left over, it goes into a smaller temporary container to be used up before going to the larger container. I have a better idea of when to buy new items this way.

I would measure what's left over, and add that number of cups to the contents of the container. Then I would shop for a container that would hold the entire volume, and "demote" the container already in my pantry to another foodstuff.

I wait until my containers are nearly empty before refilling. If there's leftover I usually put it in a reuseable ziplock bag and store it in the freezer. (I try not to buy too much extra, as I'm only cooking for 2 and don't go through it all that fast. The exception is flour.)

I swap them around. When an item is low, I move it to a smaller container. The larger one is then available for something that needs the space. For the things I buy in large quantities, I have two containers. A medium sized one the is close at hand and easy to move and a giant one that is stored in a more out of the way place that I only need to take out to refill the smaller one.

Something else to consider is buying your staples in bulk at a place that will let you "tare" (weigh and mark the weight of) your container. Then you just fill up the container from the bulk bins and voila! No overage. Whole Foods will weigh your containers for you at the customer service counter near the entrance, if that's the most convenient source for bulk staples. Not all WFMs have bulk. I've found a wide variety from store to store, as well, in how many bulk items they offer. I keep the tare weight markings on the jars, with a sticker of piece of tape on the bottom with the item name and bulk store product number, which makes it super simple to refill.

I do this for spices, beans, specialty flours, grains, and rice. For items like honey and maple syrup whose containers need to be washed, I put the tape identifier on the top and wash the mason jar lid by hand. Then I put the jar with its labeled lid into a shopping bag for use when I go to the bulk store again. (I'm grateful that our best bulk food source - Simply Bulk in Longmont, for you Boulder County readers - is two blocks from our first-rate library, and a 2 minute drive from a fine, old-school butcher shop named, I'm not making this up, "Your Butcher Frank".) ;o)

I chose my containers with the product I wished to store in mind- specifically so I would not run into that problem. Primarily I use large mouth canning jars. I use gallon size glass jars for bulk stuff like sugar and flour, half gallon size for oatmeal and such, as well as smaller quarts and pints to suit the need. If you use canning jars, and you own a vacuum sealer, there is an attachment you can use to put a vacuum seal on the jars as well. I find that useful for stuff like dried fruits and such that I won't be using on a daily basis, which keeps it dry and critter free. Since it's my pantry, I choose containers for functionality and not beauty of display. Not to say things can't be beautiful as well as efficient, but I refuse to compromise on function. My pantry is pleasing to my eye, but perhaps not Instagram-worthy, and that's fine by me.

Another way to think this out, Jody.
How much of the ingredients do you need or comfortably use between shopping for their common sizes?
Then scale up two or three containers for the ones that need largest capacity, or scale down your shopping, or some balance between the two.

I use a sturdy plastic bin in which I neatly organize all the partial bags up, so it's all seen. https://www.containerstore.com/s/white-plastic-storage-bins-with-handles/d?q=White%20Plastic%20Storage%20Bins%20With%20Handles&productId=11005645. (Actually, I have two of them, as my pantry is stocked with eight different flours, a large assortment of nuts and seeds from nuts.com, bags of pulses and rice, etc., from the Indian grocer, etc.) I sit each bin on one of these (of which I have many, to maximize all of the space between shelves throughout the pantry): https://www.ikea.com/us/en/p/variera-shelf-insert-white-60136623/
I highly recommend both products. Those, along with a couple dozen each of quart and pint mason jars, keep my pantry quite tidy. ;o)

I feel your pain. Right now I have a clear container with sugar, and 1/3 bag of sugar on the shelf. (I just use that first.) In general, I like decanting supplies into containers, but I have had this problem, too.