I carry keys on a carabiner hooked to my belt loop. It’s handy because my job often has me carrying equipment in and out of doors. I’ve found when carrying items, it’s much easier to access my keys from the belt loop versus inside my pockets. The problem is, it results in a heavy “jingle” factor.
To combat this, I super-glued small magnets from Amazon to each side of my keys. The keys no longer jingle, and take up less space than alternatives like rubber key covers.