I use a shoulder strap (Blackrapid) and a hand strap (Canon E1).
Ditto, except I use the BR wrist strap instead of the Canon hand strap.
The RSS L-bracket stays permanently attached to the grip on my 5DIII. I have a 1" clamp permanently attached to the BR shoulder strap.
There are three basic scenarios.
Either the camera (with grip and L-bracket) is mounted to a tripod (either via L-bracket or lens mount), in which case there's no strap attached to it.
Or I'm hand-holding the camera with the grip attached and the BR shoulder strap attached to either the L-bracket or the lens mount.
Or I'm going lightweight and I've removed the grip (but left the L-bracket attached to the grip) and I've attached the RSS wrist strap to the camera's tripod lug. And I'm almost guaranteed to be shooting with the Shorty McForty.