I just use one of those "lobster claw" clips, and a few metal splitrings attached to the bottom of that. The contraption holds two apartment keys, an Ace key (I forgot what it goes to), a blue Glow Ring, a green Glow Ring, and a couple of hard plastic key fobs. One says "710 KIRO NEWSRADIO" on it; probably from the Mariners home closer last year (they moved to a station I don't pick up this year); the other says "LIVING PROUD" and has the guy-in-a-wheelchair graphic in the center.
The "lobster claw" fits onto a metal ring on the steering arm of my wheelchair; it also fits the hole in the "ignition" key in my alternate steering arm. And it clips onto the finger guard of the steering device I used at the rest home while I was there - but that steering device broke not three minutes after I first drove it into the rest home, so I don't use it anymore. I still have the same keyring though - so that hasn't changed.