Gather a high-voltage power source, primary coil wire, secondary coil wire, a top-load toroid or sphere, a capacitor bank, a spark gap or solid-state switching circuit, a base, and proper insulation materials
Design the secondary coil with many turns of fine insulated wire on a nonconductive tube
Build the primary coil with a few turns of thick wire positioned around the base of the secondary coil
Mount the secondary coil vertically on an insulated base
Attach the top-load toroid or sphere to the top of the secondary coil
Connect the secondary coil bottom to ground
Assemble the capacitor bank and switching element for the primary circuit
Connect the power source to the primary circuit through the switch or spark gap
Tune the primary and secondary circuits to the same resonant frequency
Add proper spacing, insulation, and shielding to reduce arcing and interference
Test the setup at low power first
Increase power gradually while monitoring heat, arcing, and stability
Use appropriate safety equipment and keep clear of the operating coil