Use a 6-9 V power supply which can give about 10 A current (more-better). It could be a good old transformer from ancient lamp devices, receivers etc.
Find a piece of graphite (a big brush from an electrical motor will do), connect it to one pole of the power supply.
Twist two wires - high resistance and non resistance - two-three coils. Connect them both (opposite ends to twisted) to another pole. Switch on and touch the twisted end of wires to the graphite (dangeR! You can damage your eyes, so use a special glasses or just blink or better turn eyes away!). After some training you will get an accurate solder point looking like a sphere. Usually no flux needed. Sometimes it's a good practice to make a deepening in the graphite and put a graphite powder there.