As for clothing, I hang them up the walls in my house. Unfortunately, that option is no longer viable as I've reached max capacity of the amount of furniture I can place. For the rest of the stuff, I decide whether to sell them (because most of them are reorderable), bury them in the ground, or swallow the pain and have it take up a row of my pocket space.
Prioritize. I'm not gonna wear heavy sweaters or coats in summer, so I sell them. I like being able to switch up my kitchen without waiting so I keep multiple appliances in different colors. I (try to) routinely use up my crafting supplies to take advantage of hot items or create DIYs for the Nook milestone thingy. Also, I force my partner to catalog all of my extra stuff on their island and then sneak away to the airport.
i think it rly depends on what your hoarding and for what reason.
before i upgraded my house to have a 2nd floor, i had a lot of issues with amount of stuff in my materials tab. branches were giving me the most grief, but they're pretty easy to get so i got rid of them (& more during the Bug Off). i used to keep some extra tools in there as well, but ive been putting my extras outside or not worrying about extras at all.
i dont keep furniture unless i know im going to use it, and since i havent even rly started with decorating my house ive just been putting furniture i may use in their respective areas (all my kitchen appliance items in the kitchen, bathroom-related things in the bathroom, etc.). if i can craft any piece of furniture with ease then i dont bother keeping it in my storage (imo its better to hoard materials than the product that materials can make since u can stack materials up to 30).
clothing is a bit difficult for me since i rly like the clothes in this game. i usually only keep things that are black, gray, white, and purple & everything else goes (unless its something that i found in a balloon and really like; in those situations i just keep the item until im able to find the color i like in able sisters or elsewhere). i also only look for styles id know i would wear at least once a week. since i dont have the wand i want yet, ive been keeping clothes that i'll put in it on the walls upstairs.
I ruthlessly pruned my clothing. That was the main problem with my storage, so getting rid of that helped a lot. Honestly, I was not going to wear certain colors of items, so that got rid of a bunch of things. Some shoes just won't work with my preferred style, so they went.
The next biggest was the critter page, and I was able to offload virtually everything at the Bug Off. All I have left now are what I need for donation as models.
As for furniture and like items, I'm mainly keeping unorderables. I will have to keep an eye on clothing purchases, though. Doesn't take long to creep up.
I try to keep only things that can't be reordered. If it isn't displayed in my house and can be re-ordered, then I sell it. Or that is the current theory. I haven't gone through my collection recently to do this.
I'll let you know when I find that out....haha! I'm the type of person that sees a piece of clothing I like and has to have all the rest of the colors of it. I know I won't wear them but for some reason I just feel like I need them all. I think I'm moving closer and closer to needing a second house!
Oh! I also feel like I need to add that I don't keep crafting materials in my house. I just keep 30 of each item on me and if I have extras I either make them into things to sell or just outright sell the materials. The only crafting materials that I don't keep on me are shells, gold, star pieces, and bamboo.
I have a problem with hoarding variants of clothing that I don't wear so I'm probably going to sell most of my stuff to nooks and then reorder when I need furniture that I'm actually going to use
I have a hoarding problem, particularly with clothes, and my solution is to make additional player characters. Doing so affords us the ability to spread out our collection and let it continue to grow. I suppose that's just enabling the problem in a sense, rather than solving it, but I personally want additional player characters anyway to make my island and its world history theme feel more lively.
If additional characters don't interest you, I feel that Hirisa has a good point regarding prioritization. It's something I've considered in the past, whether to sell seasonally inappropriate clothes to make room and just reorder them later. Ranking by priority works for more than just clothes too, some cheap furniture item is more easily parted with than something that costs 100,000 bells.
Elaborating a little more, I live on the verge of having my storage full and from time to time I try to sell some stuff or take away some clothes I'm unsure about...still I keep getting more stuff shortly after so it helps very little.
Atm I even try to keep lots of stuff I have for trading on my beach (is a mess ugh) so I can have a little more space but it's clear at some point I have to do somekind of very serious Marie Kondo cleaning around siiigh
Edit: Just realized this don't help much, sorry about that
I don't want to create a new character just for storage, so I constantly purge clothes only to find and buy new ones. It's an endless closet-clogging cycle. I know I don't need all 6 colors of the same shirt but I just couldn't find myself to sell them, even if my intention was just to catalog them.
But anyway, I do a weekly storage cleanout. I sell duplicate furniture I got over the week and clothes that I bought which I never once wore.
In NewLeaf I made two different homes to store stuff. And I only stored stuff that was unorderable. Anything that could be bought, I just sold and would buy later if I really wanted it. You can do the same for NH.
I’m getting close to my limits, and I know that I’m going to have to seriously cut back on my clothing. I don’t wear the vast majority of it, and a lot of it I only bought to catalog. Thinking that I might do a giveaway when it’s time to rid myself of it all, but not having space to lay down a bunch of mystery presents is a pain too D: