Same experience here as many others , I find usually once the insulation is scored with a blade and you bend it its ready to break off ,
For solid core or heavier duty power wiring I was shown a quick way by an old TV repair man who I was sent on work experience with during college . Just take your usual close cutting snips , place it on the wire with the extra protruding on the cutting side ,apply light pressure to the jaws and grasping the wire firmly ,strip the insulation , again as previously said ,you have to get a feel for it . Different cable insulations require different approaches , PTFE tends to require light scoring first or it just stretches all out of shape , some of the more elasticy plastics are the same . Others neatly break where you want it too without having to score with a blade .
I do also use the rolling between thumb and blade method ,but I generally use a blunter blade in that case so if my finger slips it doesnt do any serious damage . Im sure we've all been caught out by a fresh Stanley blade or scalpel a few times , at least its a clean cut so if you sanitise it properly and dress the wound it all heals back up in no time .