Building a common mode choke

Hi

First off, I'm a bit of a noob when it comes to electronics but I would like to do a bit of experimenting building a mains power conditioner using a cmc and X class capacitors.
I want to try different inductance values for the cmc and (to keep costs down) want to build my own cmc's.
Can anyone point me to information on how to build a cmc using toroid's or offer any advice on how to proceed?

thanks

Tim

noob + mains power =