I use one of these
The one I have locks in place so when I'm on the bottom, I keep the lanyard extended. Then I attach a key ring to the housing itself, and clip the brass clip to the keyring. It works like a charm. I also have a double brass clip that I attach the camera directly to a D-Ring on my chest (on my BC), if I'm descending or ascending in a strong current. This way, I can see that the camera is RIGHT THERE.

The one I have locks in place so when I'm on the bottom, I keep the lanyard extended. Then I attach a key ring to the housing itself, and clip the brass clip to the keyring. It works like a charm. I also have a double brass clip that I attach the camera directly to a D-Ring on my chest (on my BC), if I'm descending or ascending in a strong current. This way, I can see that the camera is RIGHT THERE.