Alissa H. Carlton, Improvisational Piecing

The supply list is incredibly simple:

• Fabric: Bring your scraps! Lots of scraps. Make sure that some are as long as 18". A series of fat quarters can work here too. It's always better to have more fabric to pick from, so err on the side of bringing more than less!
• Sewing machine
• Piecing thread
• Cutting Mat
• Rotary Cutter
• Ruler

Alissa's website provides more information.