Well, slips are the sprouts of the whole potato. I just filled a tub with soil and waited to see growth. When about 4-6", I slipped. My fingers in the dirt and slipped the sprouts off the main potato. Very simpłe. I guess that way you can have more plants sine each one will give you several slips.
I did plant the extra slips today in another garden area. We'll have plenty to keep and sell!