I've got a similar growth drection also and a similar suze neck. +1 on syslight with the scything stroke except I pull the skin tight from the jaw bone to re-direct the har growth to an angle from my ear to agams apple. Then I ahave onthat angle. I can fit the blade across my neck on an angle but not from jaw to chest. Scything and blade buffing help a lot. Lastly I relax the skin and look straight at the mirror. With what would be XTG I very lightly do scythiing strokes arount the sides of the adams apple to get the last few hairs. The sharper the blade the better I find the results. Oh, the past part I do with water only and sometines dry, but be extra careful