In this tutorial I will show you how to illustrate a polygonal portrait of a dog (Jack Russell terrier) in Adobe Illustrator. It is taken in two parts, you are watching PART 1. You can find the finished illustration here on Polar Vectors inside of a beautiful seamless pattern collection My Daily Dog Patterns!
Image of a dog that I`m using as a reference is taken by Irene Davila (Unsplash.com).