Beginner move, you go through the box, check all cables, and do one of two things:
Get rid of all duplicates but keep one of each type of cable.
Catalog and label all cables in the box, make a list of all cables including their numbers. List all known devices that use them, index their usefullness based on how many devices you know use them and how long ago it was that you needed them. The more usefull the cable the more copies you keep, but you allways keep one type.
I will pay you to come over and handle my cables. I really like idea number 2, but I have nearly 4 decades of computer cables and 3 decades of audio cables that have gone through several moves. I don't have the energy or attention span to go through them.
I totally would if I could. However, every attempt I've made has ended after a few hours of me trying to see what cable goes with what, testing XLR, TRS, and TS cables, getting distracted, then having a messed up garage for weeks until I put away the boxes of cables.
At least I learned my lesson about trying to combine those boxes with my current known good cables that I use for my PA system. That was a bad weekend.
My problem is repeatedly getting distracted. My other problem is that I have more audio cables than I will need in my whole life. Ok, I have a whole lot of problems when it comes to this. It's my great shame because I'm pretty good at keeping most everything else in order these days.
I have a good sized box of electronics cables. I have three ~80gal storage totes with wheels and one cardboard box full of speaker cables, instrument cables, mic cables, adapters to plug in different devices to PA systems, several wireless receivers that I'm not entirely sure what they go with, and other miscellaneous cables, and I'm not sure how much of it works, how much I can solder back together, and how much just needs to be thrown out. That doesn't include the smaller tote with my current gear that I bring to gigs.
While writing this comment I realize I could probably just test them with a multimeter, but in the past I've plugged them in. This leads to me noodling on the guitar and losing the thread of what I'm doing.
Ideally, I'd get an extra set of cables as a just in case measure, fix what I can fix, and donate all the good ones I don't use to a broke musician just starting out. But my hyper focus has never manifested in a way that lets me just fucking get it done. I just make a mess and play guitar before giving up several days later and putting it all back because I need to do things in my garage.
Computer cables are also fairly easy, unless you are into retro computing you can probably throw out all IDE and SCSI cables, they are useless if you have a computer without the relevant connector anyway, so keep one of each if you are unsure, same goes for old centronics printer cables, cat4 networking cable will work, but only at very slow speeds, throw it out and use cat5e for general purpose, serial (RS232) is useful, keep some, power brick are allways useful, keep them all, USB cables are cheap, replace any USB1 cables with a minimum of a USB2 cable, male USB-A to male USB-A were used before mini USB came along, keep one as a spare, mini USB is still in limited use today, keep 2, micro USB has many different connectors and types, keep 2 normal and one of each of the odd standards.
Video cables: VGA - keep one spare, DVI is still useful, keep two, HDMI/DP - keep but beware that they might not work with the latest specs of the standard. Component, there is little need for it these days, depending on if the cable has a custom connector used for a gaming console or other device, keep, else no need to keep them, composite is the same as above. S-Video same as above.
This might sound harsh, but unless you are into retro computing or retro gaming you mostly won't need old computer/video cables.
I am an IT guy, my dad is a civil engineer, I get keeping old cables just incase, I have component cables to my PS2 that has almost never been used, the PS2 is from the last slim version, I have an almost brand new original gamecube controller, I have component cables for gamecube that has never been used, I have countless power bricks that I never use, i have a super long cat5e cable that I built when I moved in to my apartment a decade ago, up untill last year I used a custom cat5e cable between my computer and the wall.
I was into retro gaming a while ago, but I have never had a TV here only an old crappy projector, that I have used once.
I am getting tired of keeping the old stuff that I never use, and will probably clear it out in a few years when my annoyance has reached boiling point, and I have more time to deal with it (I am not planning on just throwing away all the stuff, that would be wasteful, when I have more time I will take inventory of all gaming stuff and make a plan on how to best deal with it)
Just get a bunch of bags or small boxes and sort them into different types, and write on the box what it has. No need to catalogue devices or deduplicate...
Change my mind: two hours of my work is more expensive than all these half defunct cables from 10 years ago. Just throw em away and buy them new when needed. You will only need one or two of them anyway. No more sticky, broken cables, no more cable sorting, no more wasted time and no wasted space.