How do you guys come up with ideas for items?

I know this is isn't the best answer but really depends on what's important to your story- my advice I guess would be not to think things are too small, the items of importance don't have to be Godkilling weapons or mythic items, they can be little things like a character's good luck charm or any item of personal significance to them, it doesn't have be be of significance to the whole world.
Sometimes I see writers so focused on world building they kinda miss the trees for the forest? Like the big things are important don't get me wrong, but the little things are what bring it to life.
Just like the real world is huge but it's still made out of molecules.

To be honest, I have like 20 item pages and all of them are weapons. However, I justify this as my main character is a draconic blacksmith that comes up with the most ridiculous, over-the-top ideas and doesn't even end up using them often. They just kinda sit in his Hoard and he maybe gets one or two good uses out of them during the story because he's fickle and can't decide what he wants to stick with. I just get my ideas from whatever silly weapon or battle mechanic I can think of, or I just steal from video games and use a different coat of paint.

i kinda just… either take a stupid thing and give it a cool name and magic or look for plot holes and fill it with a magical solution item

Really, I just like to flip through DnD books for things I think are neat. Otherwise, I just look at it with the question: if I was this person, what would I think to be the coolest thing ever? What is the problem I have as this person? What would be the closest thing I could make to it while sticking to the rules of that world?
This is how I came up with a top hat that can store entire piano's and stuff because the character I made it for would want an easy way to carry her instruments while still looking fabulous.

I actually have THREE items, and one of them is a vehicle bc I don't have premium… but I make up stuff in my head all the time, so there's that…

It depends on what kind of story you're writing. If it's fantasy you can have things revolving around magic, weapons are also something that can be a thing. But if it's like, a romance, or a coming of age kind of story, then I suggest doing something important to your character or something that you could throw back to later on in the story. For example, a necklace from someone important, a picture in a frame, photo booth pictures, old drawings, diaries, that kind of thing. Things with sentimental value that play a role in your character. Like if they wear a necklace constantly or have a worn old picture of their sibling that's started to go yellow around the edges tucked into their wallet. Y'know, that kind of thing

I specialise in fantacy so this might be a little biased to that genre, fantacy lets you get away with all sorts of funky things.

When I'm looking for item ideas I start of with a little exercise, take an already existing completely ordinary thing and make it weird or stupid. For example the Cloff is a ring forged of magic and fools gold that tells the wearer the time by changing colours (in other words, a mood ring) I used fools gold because I think it's cool and fools gold is extremely common so when you have common material you have common object.

If you are looking for something more powerful and daresay more useful than a colour changing ring first look at what it does, will it explode on impact will it turn into a giant toad and swallow your enemy for you or will it just make you the perfect coffee. Look at items from mythology Greek and Roman mythology to be exact their stuff is crazy good inspiration.

How it looks can sometimes be a little difficult, I usually describe very few things about the weapon whilst in use, unless it shatters or something. the rusted handle was becoming more and more invisible as it was craftily swung through the smoke filled air by none other than….

Names, names are fun I enjoy naming my things so this is just second nature to me. What I like to do is stop for a few seconds and listen for funky sounds like maybe wind blowing against trees and now you have a shrackle- a random weapon I made up on the spot, an original version being (shhhkkhra) sounds like a baby trying to say something doesn't it.

For deciding how rare or common it is I usually decide given on how long it took me to come up with a name or what it looks like etc: but for example everyone has a cloff because I whipped that thing up in 5 seconds whilst the shrackle is only used by professional sword fighters (do you know how difficult it is to turn shhhhhkkhra into a word) but that's the fun part.

I hope this lengthy message helped out and if I missed something you want to know tell me and I'll add it here.

I mostly do specific Magic Weapons for some of my major character. Like my characters each get a specific themed weapon to match their powers. That's basically it. I also kinda have only 3 items, so…