wheel chair/ strap/or nothing
I go the no strap route, using thumb & forefinger for control. Haven't had a mishap yet. Never seen a person use a tray, and some pro's use straps, others don't. The straps that come with the radios (at least those below the 9Z & 10X) come with el-cheapo ones that are difficult to use. The aftermarket's are nice because of the spring swivel snaps - you can leave them on your neck and easily connect/disconnect the radio, but then you've got to be careful not to get it caught in the prop when you're leaning over the plane.