I have always used the notches on the scissors and had them work perfectly fine without any broken conductors due to nicking the copper, I have seen people trying to use the notched and doing nothing but cutting the wire shorter and shorter so I guess it is definitely something that you have to get a feel for. I lay the conductor in the corresponding notch either 22 or 24 ga like Haligan said and put my finger on the other side of the conductor and pull, you have tyo have the flat side of the scissors pointing towards the direction you are applying pressure to strip the wire.
