Create a Plaid or Tartan Pattern in Adobe Illustrator - A Graphic Design for Lun

Very good instructions for this class. Also, the bonus lesson was nice; may help somone create mockups.
I used a two-tone plaid, not realizing some of the steps taken would be best learned using a 3 or 4 color plaid. I went forward with what I had, intending to go back in and create more variation.
The recolor tool is fun to use. I recommend this instructor for Adobe Illustrator.