In reply to slothlord:
Disclaimer - Ditto all said above.
However good bivvy spots can be found all along the central ridge of the Cuttings Boulderfield. The Highball Wall is also quiet and there flat space for two to bivvy there. Don't stay in the stone huts, they're usually a little on the grim side.
The Southwell Landslips are also pretty quiet most of the time and rarely frequented even by climbers.
Most secluded and considerate bivvy spots are to be found in Battleship beach area.
Alternatively consider bivvying down at Winspit, lots of excellent secluded bivvy spots to be found down there.
Post edited at 19:06