For this years sheet mulch potato plot I picked a weedy area where nothing had been previously been grown.

why sheet mulch potatos?  Because when it is time to pick your new potatos they will be easy to pick since they will all be on top of the cardboard.

Lay out your cardboard.
I then sprayed it with water.
Add soil or in my case OMRI listed organic potting soil (price was right)
Add your seed potatos to the soil, cover them with soil.
Water the soil.
Add some mulch over the soil – you want to make sure your new growing potatos never get sunlight as they will turn green and be toxic. You may need to add more soil as the potatos grow. I used pine needs for mulch since I had access to some and they stay put when the wind blows.
If you cut your potatos you need to let them dry a day or two until the cut areas dry. In wet area you may need to dust them with maybe sulfur.