Alan
I think a lot depends on the size of the A/c and whether it's affected by Noise limitations.
Non-noise - go off in whichever direction you require subject to good-neighbourliness.
Noise limited, then you would follow the SDR (if there is one) until at a level - say 3,000' - when NPR's no longer apply, then own-nav to the chosen waypoint.
If you need to be noise-compliant but without SDRs, then I would suggest that a radar heading approximating to the NPR until at a non-noise limited level would be the sensible option.
In the absense of procedures, I find operators/crews ask "what would you like us to do on departure?"
Tori
