Bare & Twist
Use a wire stripper or small knife to strip away a small part of the insulation at the end of the wire.
If you are using a knife, try putting the wire on a hard surface, then gently rolling the knife over it where you want the insulating cover to be cut. If all the surface is scored then the plastic covering will usually pull away quite easily.
Wire strippers are a lot less fuss and save a lot of time if you are doing many wire-stripping operations.
This will leave the fine metal wires exposed. They may already be neatly twisted around each other, but usually not.
An easy method to get this twist is to hold the bare wires between thumb and two fingers of one hand and gently roll the rest of the wire between finger and thumb of the other hand. Let the bare wires rotate a little, but apply just enough pressure so they twist into one piece.
This makes them much stronger and easier to deal with.