Step #1: PrevNext
The first thing is to make the big coil. You can do this by putting four nails into a board and wrapping the copper wire around them.
Step #2: PrevNext
Then you have to make the smaller coil. It has to be about half the size of the bigger one. You need to put an LED/bulb and a capacitor on the output. I put 2 because I didn't have one that had the right value. You could also put a bridge rectifier on it to turn the AC into DC.
Step #3: PrevNext
Connect the power to the big coil and put the small one in the middle and the LED should light up.
Step #4: PrevNext
I tested different gauge wire and the maximum efficiently I got was 42.2%.