Square 2 Circle - Sample
Naturally the question being, where in the hell will this be used, well this is an example of an area that I want to control the lines within the radius of the object.
I find this to be much better, for me, to get the control for the flow of colour around the tire. Once completed then I will make a second one below and stitch it with the colour.
This layer will be below the rim/fender so I don't have to pay all that much attention to the center, Using the "ShiftKey" and moving the points on the edge will allow me to maintain the clean edge. I picked this up by trial and error, no books. Useless, maybe but I use it a lot.