The benefits of dividing a circle into sectors - eg. multiples of fractions of 360 degrees like 30 or 45. These then give you axes of symmetry, in which to reflect design elements into a mandala.
To divide the circle, reflect drawn radius from a central anchor point OR you can use the Polar Grid Tool to do the same but with lovely precise guide lines.
The key to all this is using the Rotate tool (r) to Alt-click on the centre (so R, alt-click) which opens up the key dialogue box. Use it's preview function to check the rotation is landing in the correct place (rotated at 30, 45, 60 or whatever), the click COPY. That transformation is stored momentarily, and Cntrl-D will paste each new iteration round the reflected point!
Little spokes (lines) can be easily rotated by saying - you need 70 strokes - the angle of rotation is 360/70