Hi Iain,
Every one has a preferred way to find the SCP, whatever works is the main thing.
Personally, I have used the Solar noon method to set up my imaging area.
If you haven't checked it out already, go to a site such as this:
http://www.esrl.noaa.gov/gmd/grad/solcalc/ and put in your co-ords etc...
Drive a stick into the ground making it straight and level. At the exact time of "your" solar noon, the sun points to the celestial pole with a shadow on the ground. Couldn't be simpler really.