Sideburn area to dome shaving?

[edge]

Hey everyone, just a question?  I shave my dome with a Fusion and/or Mach3 razor, then I will shave face, neck, and tidy-up around the ears with a Excel Sensor which works great, however, I just started to shave against the grain for the dome and am getting smooth results, but my only issue is where should you start/stop the against-the-grain shave for the dome at the sideburns area? I cannot shave against the grain at neck and face as produces ingrown hairs so am seeking that perfect seamless transition from sideburn area to dome.

[D.A.L.U.I.]

Start w/ the top of the ear, then gradually work down until problems appear--that is the point.

[ozzie]

Where you can feel the cheekbone, right next to the ear is the point of no-return for me.