I've been a seed-saver for decades.... When I collect seeds I use paper bags for larger flowerheads like dictamnus, sweet william, etc. I use plastic containers from yogurt/sour cream, etc., to collect most seeds, and it's also what I use to ferment my tomato seeds. Once tomato seeds are fermented, I lay them out on a piece of paper towel on a plate to finish drying, then once fully dry, I store them in small plastic ziplock-style craft bags. Other seeds (e.g., peppers, cilantro, etc) stay in those open containers until they are fully dry, then they also get moved to plastic bags. All seeds are marked with variety and year/date of collection. I then collect packets into like categories: tomatoes in one big bag/container, peppers in another, herbs in another, etc. Then all larger bags/containers go into a larger bag/container and they're all stored in my fridge. :)

ETA: with my method, tomato seeds still have excellent germination rates even after 10 years.

How to preserve bird seeds that you should know how to do. If you are using a metal container, ideally it should be galvanized, as this can prevent rust from forming on the outside and inside. Containers with watertight lids are also a necessity to minimize the risk of mold. Using weights or nylon rope to tighten the containers can ensure that rodents and insects can find their way inside.

I have a cabinet with LOTS of small drawers. It's kept is a cool room in the house. This past year I used old prescription medicine bottles for keeping saved seeds. I have an Excel spread sheet to keep track on my seeds.

The storage of bird seeds is different depending on the climate. When it is very hot, it is better to store a quantity that the birds can consume for two weeks during the summer season. This method prevents the seed from spoilage because of humidity and hot conditions. During the winter, you can store seeds that the birds can consume for four weeks.

I keep my seeds in plastic food storage containers. Now it's up to three containers. I file the seeds alphabetically, like old library card catalogues. I store them in a cool part of my house, which stays at fridge temperatures in winter, and cool room temperature most of the year, and warm for a month or two. They stay good and viable for several years.

My own collected seeds, I used to keep in paper envelopes I'd fold myself from waste paper. Last year I finally bought small plastic zip seal bags. I dry my collected seeds for a few weeks before putting them in plastic. Basically in late summer, my house has plates and bowls of drying seeds perched on every available surface.

I love sharing seeds with others. Home-collected seeds are so abundant, and in my experience often have much better germination rates than purchased packets. So, since last year, I've starting saving the well-dried seeds in tiny zip bags (about 1x1.5 inch), several of these inside a larger zip bag (2x3 inches). I jot the variety name and year of collection on little rectangles of paper and put these inside each small bag. This way if a friend expresses interest in seeds, I have small labelled bags ready to give away.

It also means that when I want to plant, I can pull out a small bag of seeds and don't have to expose the rest of the stored seeds to summer heat and humidity while I get around to sowing and putting the unplanted portion back.

When one variety of seeds I collected is a really large volume, I do put it into a reused jar (after drying well for a few weeks, of course). But then the random jars tend to get lost, so I'm trying to move all seeds into flat packs in my alphabetized plastic boxes.

Home collected seeds that have been doing great for me:

* Cherry tomatoes and open-pollinated tomatoes (tomatoes tend to self-pollinate so they're easy to save). I still buy some hybrid varieties like Sungold, but those seeds last for years so I don't buy new every year.

* Lettuce. Each year, or at different times with a year, I let one variety that I like go to seed, and save those seeds. They produce lots and last for years so this works well for me. I've also done two varieties of spinach now, in two different years.

* Arugula/rocket (Eruca). This bolts so fast and sets seed so fast, that it's really easy. And there aren't significantly different varieties to worry about. The volunteer self-seeded plants are also useful.

* Winter squash of the Cucurbita maxima species. Another very easy one to save. Even if it were to cross-pollinate with a neighbor's C. maxima, they are all edible winter squash so the result would be very likely good. I don't have any neighbors growing this species so I have no worries. The seeds last for many years, so when I have grown different varieties that I don't want crosses from, then the next year I just replant the seed from a previous year that I know I liked.

* Flowers and herbs like marigold, bachelors buttons/ cornflower, cosmos, poppies, edible chrysanthemum, nasturtium, zinnia, dragonhead, hollyhocks, summer savory, cilantro/coriander, basil, anise hyssop, fennel, perennial scallions, orach, etc. Very easy. I stick to one variety of each species so that I can save seeds, and/or let a few of their self-seeded volunteers grow. I do try to deadhead the spent flowers as much as possible, but by late summer they get past me and then I collect seeds.

I keep most of my seed in a deep filing drawer in my office desk. It's fairly climate controlled and very secure from vermin. I use the drawer divider to keep the back for bulkier packets like saved seed and where I toss this seasons used up packets.

In the front of the drawer is two 10 pound tomato lugs stacked and four tall square popcorn boxes, the theatre eating kind. In the lugs are the eating seed, I use paper lunch bags torn off at the top to help keep them organized into catagories in one lug. The other is mostly bulkier microgreeens, greens, and herbs. The popcorn boxes are for flowers and broken down into weeks to start so I can just pull out that box when it's time to start that round of flower seed.

I also keep some seed on the other side of my office. I have a built in bookcase where I keep my cookbooks, and quite often there lives a small collection of plates and jars of random collected seed. It's a good place for laying out seeds for drying. Not organized at all. But I am usually good about keeping tags with the seed till I get it cleaned up proper and into paper packets.

I used to have a much bigger and messier collection. From trading, and sampling and getting stuff and partial packets, and ugh. So I did a hard culling out a couple years ago and purged down to the current drawer. Last winter I purged again to tidy up and really get down to what I'm using and not just having. This spring that lot is getting tossed out to the "eff it" area of the backyard. A corner of the stableyard that I'm starting to convert to gardens. If the seeds do something out there, great, and if they don't, eff it.

When I'm collecting seed and it's big stuff that sits in paper grocery bags for a while, those tend to sit in my sewing room for a while since the living room tends to be decorated at the time. Then they start to sit in the living room as I get the bags shucked down while watching TV. It's good for my late winter garden jitters along with microgreen growing :)

I keep my seeds in 2 ways. I will keep a ball jar with enough seeds for an entire garden, in paper envelopes, in the freezer, with the year written on it. This is because I am on a 3 year rotation with my varieties, and I can just grab the container that's next in rotation.

My backup seed is also kept in paper envelopes, but it's separated by category...squash in 1 jar. tomatoes in another, etc...I have more seeds in a packet, and several duplicates,so if I need a variety I can pull it from the jar and put the rest back in deep freeze.

I also have a running list of my varieties.

I recommend different methods for different seeds. Metal lard cans (metal) in a cool spot like a basement work well for most vegetables. I’ve kept tomatoes and pepper seeds in them for up to 15 years. Many herbs, flower & onion seeds need to be kept in a freezer to even hold 1 year.

Be sure to keep a record ( seed inventory) indicating among other things where your seed is stored.

My working seeds (those for planting and sharing) are stored in zippered freezer bags, which are then rolled to expel excess air, and packed into metal file cabinets. Those seeds are in a climate-controlled room, and are generally good for at least 5 years. Because I have a large collection, there are separate drawers for each species/family, sometimes sub-divided alphabetically into multiple drawers (as for beans). For small seeds such as tomatoes & peppers, the freezer bags are enclosed in large file envelopes, stacked on edge within the drawers.

For the rarest varieties, I keep backups (in single-use quantities) in small sealed plastic envelopes, which are then packed within sealed ball jars. Those seeds are frozen at 0 F. degrees. It is important to emphasize that seed must be dried to a low moisture level before freezing, the container should be air tight, and that the seed must me warmed to room temperature before opening. Exposing cold seed to warm air can result in condensation on the seeds, which could potentially destroy them. The same precautions apply to seeds received in the mail during freezing temperatures. I should also mention that freezers that self defrost are poorly suited to long-term seed storage; chest freezers are best.

Whatever method & container you choose for long-term storage, it is wise to place a label inside with the seeds - preferably in pencil. Ink fades, labels fall off, and you don't want to end up with "mystery seeds" in the future.