I try to find people to sell or give it away to. Like the bunch of gyroids I sold to the poster above. I figure that no matter how worthless something seems, there's probably someone looking for it.
My first instinct is to sell it to Reese, but if I thought it would look good in villager's home I might send it to them in a letter. Whenever I get the pay it forward initiative, I literally "pay" it forward and just send them bells. I have never seen a villager put bells in their room, so I figured it was a safe option.
I usually sell it to Retail, and definitely do if it's an item I can buy on my catalog. Unorderables are a little harder to part with, but I've started selling or mailing items I know I won't use myself. If I think I might be using the item I give it to one of my alt characters to hold on to until I decide what to do with it.
sell at re-tail! if they are things I think ppl will want/items I may use in the future then I keep them in storage. rn I am lazy and have a bunch of random items on my beach that I need to tuck away
For items that can be reorder I send some to my other towns. When it's cleaning the closet I usually throw orderable items in the trash can. I'm trying to keep my towns clear of trash.
All non orderable items are in my players saved mail. For the meow coupons I stopped buying all the items. Just get what I need. There is a lot of time to get the other items later for cataloging.
If it's something that's not rare, I usually just sell it at either Re-Tail or Timmy and Tommy's. If it's something that IS rare, then I store it in a closet (and probably the hidden storage when I unlock it).
I do try to sell on here, some people really are looking even for simply T&T items...but just like with villagers, it usually just ends up taking more time than I'd want, so I probably would give it to Reese at that point.
I trash them, I let villagers ping me to take it, and I send them as gifts in letters. But I mostly just trash them, I'm pretty lazy when it comes to that.