Mine is clipped on the TOP of my left PFD shoulder strap, with an extra carabiner attaching it to the PFD loop nearby. I forget it's there but easy to grab.
I keep mine in a CMC Radio Holster. It attaches securely to the shoulder strap of my Mocke PFD. Stays out of the way and is easy to access. www.cmcpro.com/equipment/radio-holster/