I wired our home myself, so I feel quite triggered to answer that question. Upfront I have to admit that in my country that kind of electrical installation - inculding switches and electrical sockets - with screws is outdated. Maybe for obvious reasons - everything is clamped. As a result, pressure on wires are limited; including solid copper core wires and flexible ones, which should be coverd with ferrules.
For removing the insulation there is a tool for everything: removing the outside insulation you use a stripping tool. The blade will only scratch that insulation - enough to it break apart when moved in different directions. The wire insulation there is different tool, but teeth can do it aswell, if you have not one around.
I even felt obliged to watch a video for anglo/american wiring. If the wire is bend around the screw, there is not much I guess you can do, but tighten gently. If a screw hole, do the same.
But as always ... never take anyone's advice unless you fully understand..but..if you don't understand then that is your problem..
the newest good sockets have screw clamps but cheaper ones still just a screw..
the first thing an electrician is thought is that if putting a single cable in a socket..with no loop in loop out..then you bend the single core back on itself into a small double core state..then when you tighten the screw it tightens evenly on the 2 cores instead of one..if only 1 core is used the screw can cut into the copper and cause a potential weak spot..thus..a potential break point..or..even worse..a saftey concern if high current is drawn by the circuit and inadequate fusing is used!
you also have to bend the copper wire the correct way..as the screw always goes in by turning it clockwise..not anti-clockwise
