I shave my head in the shower without a mirror. I do it all by feel. I shave exclusievely against the grain, including the sides. I only use my Headblade (even on my neck and face).
If you wear the Headblade as recommended and shave with one hand and use your fingertips from the other hand to check fro grain direction and stubble you can pretty effectively kill all the texture and get a clean, close shave.
Just be open to changing the direction of your stroke and not always doping long full scalp strokes
