If you’ll excuse the aeronautical term, the angle of the blade have been somewhat on my mind lately – not the angle it has in regards to the razor (which differs between various razors), but the angle it has in regards to the skin when it cuts.
It is – like many other things – the fault of the cartridge shaving systems… the so called modern razor tends to have a flexible head, which is supposed to make shaving easier. A cartridge razor teaches us a lot of bad habits – use of excessive pressure is the one mentioned most often, but just as bad is the lack of proper angle… and when shaving DE (or SE) the angle of attack is alpha and omega in my opinion for getting that great shave.
The head of a traditional safety razor does NOT pivot. Therefore the pivoting action have to come from the wrist – making shaving a little more labour intensive, but more importantly giving the shaver near perfect control… unlike a wibbly-wobbly plastic hinge.
Maintain proper AoA at all times – and check your six for bogeys.
/ for a more complete discussion on the how and why of the shaving angle, please see this article over at the Badger & Blade wiki