I LOVE organizing. It’s somewhat of an issue as it turns into a time suck that I could probably be spending doing other things. Some back story to my “system” though, is that I inherited my horse and as such, all of his things from his previous owner. Therefore I own 3 full-sized trunks, but I only purchased 1 of them so don’t judge me
My big custom wooden trunk I had made for me is the trunk that lives in front of my horse’s stall. It has a sliding tray in the top, and a “hidden” drawer built into the trim on the bottom of the trunk (I can post pictures if anyone is super interested). In this trunk I keep my day-to-day things that I like to have easily accessible. On the side “under” the sliding tray I keep my horse’s expensive accessories that I don’t want hanging out exposed to the rest of the barn (his BoT sheet, wraps & boots, equifits etc). Then on the “open” side not under the tray, I keep his grooming bag (ariat mini carry-all) my paddock boots & 1/2 chaps, and an 8 qt bucket with all his bathing supplies. In the tray I keep small odds & ends that would get lost in the bottom of a big trunk. So things like gloves, hair nets/ties, spurs, a couple small first aid items, bit wipes etc. In the hidden drawer I keep back-up odds and ends, like extra hair nets, gloves, a couple bits I rotate through sometimes, and other small items I don’t use as frequently, but like to have within reach in a pinch.
Then I have a small (re: it might be 1’x2’) sport-tote trunk which has all of my horse’s schooling boots and bell boots in it. This way sand and whatnot doesn’t get tracked into my nice trunk, and the small trunk is small and light enough to dump out when it gets gross, or hose off to clean up. This trunk lives under my saddle racks which are in a different spot from my big trunk. I also have shelving space above my saddles, so there I keep one medium sized tupperware that houses all my first aid supplies. Then a smaller tupperware that I keep all of my tack cleaning products in, and a smaller tupperware bucket with a lid that keeps all of his cookies. We use a leaf blower to clean the aisle at our barn, so I’ve found compartmentalizing things in tupperware helps to keep them clean and dust/dirt free.
Then in our storage loft I have two additional big trunks - a stanley and a big blue sportote. One I keep all extra “horse” stuff, back up blankets, saddle pads, tack I’m not using etc. The other one has extra “rider” stuff I’m not using, like winter barn jackets, extra boots, gloves etc. Also with those, I have a rubbermaid tub about the size of the bins you get when you go to college. This one I keep all of my “off property” things, like the cooler I only use for shows, standing wraps, a mini first aid kit, my show boots etc. And lastly, a medium tupperware tote that has all of my horse’s supplements (I mix my own “smarpaks”).
Basically my system is such that the things I need daily are easily within reach at all times, and the things I don’t need are filed away where I can get at them if I need them, but they’re not filling up space in my daily-use trunk. I find that keeping the number of things in my daily trunk limited helps me stay more organized and doesn’t result in a ton of clutter to manage. I know where everything is, and everything has a place.
Try to think about what you need to have your hands on EVERY time you’re at the barn, and organize that stuff first. Then look at what’s leftover, can some of it go home? Can some of it go in another bin so it’s not “floating” in your trunk? Can you re-sell some of it (my favorite way of organizing!!) Once you kind of have your “tiers” of items, it becomes easier to organize. I love Target and the container store for finding different sized bins and totes. Marshalls and TJ Maxx often have cute boxes too, but I’m OCD and I like all of my containers to match! Hopefully this helps, and happy organizing