Step 2: Straightening the Wire
To ensure you get a smooth rolling track you'll have to straighten the wire before you start making (especially if you've acquired old bits from skips / other sources)
To do this, first strip a length of wire (~50 - 100cm)
Next affix one end to something fairly solid (like a vice, or a piece of wood you can hold)
Attach the other end to your battery drill.
Tension the wire by pulling the two ends apart, and spin the drill slowly. Don't go mad here - you will be able to see when the wire has twists in it and has straightened out.