Thanks for the feedback guys.
The tools were very easy. I used a small LED torch attached to a piece of strong string. Set the camera on tripod on a bulb exposure. Start spinning the light source in front of f you looking down to see where the bottom point meets the ground.
Start the exposure then start moving in 360 degrees making sure to over go over the same spot at the bottom and stop the exposure at the end of the 360 turn.
Settings and kit used were Hama travel pro tripod, canon wired shutter control, 650D, EFS 10-22 at 10mm, 44s exposure at f/7.1 ISO100. Some post processing (clarity, temp and detail) in Lightroom. Another test worked well at f/5 too. If the weather is good I'll venture out this weekend for some more tests.
Definitely want to try other locations and colour variations. Also thinking of ideas to make other shapes.
First attempt (ok it was third or so!)