I usually have mine on a carabiner on a belt loop.
I use a “brass pull-apart” key ring. Car key/fob on one ring, mini multi-tool and door key on the other.
In my pocket on a heavy steel split-ring I’ve used for 40 years. But that’s just the set that has the truck key, work keys, house key, locker key, tool box key, Fenix E01 flashlight and a threaded cotterpin from my first boat on it. The other set has the car key/fob, SAK, house key and storage unit key on it. Which set goes into the pocket depends on where I am going and what I am driving.
Dump them in my handbag.
I do the same. It keeps me from constantly misplacing them.
As above, heavy steel ring with the minimal set. (truck, house, cabin, boat, RV, desk, and a few padlocks and coupler locks that I frequently operate) Eight total. Always in my pocket or on the nightstand.
On a keyring.
I have only 4 keys, truck, house and 2 house keys for clients I visit on a regular basis.
I clicker thingie to unlock and lock the truck doors.
However I have one credit card, 3 store cards and 3 Wendy’s free frosty cards on the ring too.
Me too, but it’s clipped into one of the holes in my belt (this type). I have a lot of keys so I’m very jingly.
I leave my keys dangling from the front door keyhole when I’m at home. Learned from lots of experience that I will lose them, otherwise.
Key ring. With a thumb drive for a fob… 
smack: (I mean, how nerdy is that?)
I think I match the nerdiness: Key ring with a password generator for my VPN.
I went through ***that ***as well… We don’t use that system for access any more, thank Og…
My house key, the grocery store loyalty tab, and my gym barcode tab on a cable keyring.
My car key on the fob from the dealer with keyless entry.
If I’m driving, I usually throw my housekeys in the cup holder until I get back home to minimize key bulk.
However, that means I never have my grocery loyalty card on me when shopping. (I live close enough to the gym that I can walk there.)
Car key, truck key, house key, and some grocery store tags fit easily into a pocket.
I seldom need to carry keys on my person - on weekdays, I’m first out of the house and last home - I do have a door key in my man-bag in case the others have gone our or something. I commute by train, so don’t habitually carry car keys.
At weekends, if I need to take a house key, I just put it in my front pocket.
Small price to pay for looking like a dork, eh? 
I keep mine in my front right pocket of my pants. I have a small set, just my house key, car key, and a small bottle opener (the essentials.) I hate having a bulky set of keys jabbing me every which way in my pocket. I really don’t understand how some people manage it. I know people who probably have close to a dozen keys, a pocketknife, bottle opener (or two,) and decorative keychains on on one set, and it goes in their pocket. Not purse, bag, or clipped to a belt-loop. Doesn’t it drive you mad?!
I also have a separate “work set” that has my two work keys and a small Leatherman. That stays in my car if I’m not at work. At work, I take it out of the car to unlock the door, then it typically stays on my desk unless I leave work to go somewhere (I do a fair amount of travel for work,) so then it goes with me and into the work car. Then it goes back with me and into my car atthe end of the day.
If it’s winter, then I keep both sets of keys in the right pocket of my coat. Since it’s a big pocket in a coat, the extra mass doesn’t bother me like it would in a pants pocket.
RV keys are on a carabiner, house keys are just on one of those metal rings attached to the car fob.
I do that too. I need the thumb drive all the time at school, and frankly I only had to pull out the SAK I had before about once a year.
Can I ask why you guys do this? Seems it would be just as easy to prevent loss or misplacement by simply dropping them in your pocket. The downsides seem vast: you could scratch something like a car while walking through a parking lot, rip fabric when sitting on upholstery, belt loops break fairly easily so the chance of loss is not insignificant, you look like a prison guard… I know several guys who do this and I cannot figure out why. Seriously, there seems to be no upside. Perhaps you gentlemen can enlighten me.
FTR I keep mine, 6 keys total, on a simple ring dropped in my pocket. Haven’t lost them yet.