I mostly just use side cutters, and don't nick the wire or any strands very often. If one gently squeezes the insulation a few times at the desired stripping point, and then give a quick flick of the wrist!
I also have several pairs of BT/GPO Pliers wiring #5 kicking around, which are long nosed pliers with a wire stripper incorporated. They're designed for 0.5mm sq but will work on small mains flex "wires" too. I have to agree about the so called automatic ones. Unless one pays an absolute fortune for some decent ones, the rest are rubbish. I have actually broken a pair of those by squeezing too hard. That might have been me though as I also did it to a pair of nutcrackers once...........
