The "Chicken Pickin' Double-Stop Etude" lesson covers a useful and common country style pattern with many permutations to develop a greater knowledge and awareness of the fretboard. It is basically an ascending and descending Major scale with an added third.
At times we also explore the added third in the first inversion (third is on the bottom). This pattern is great for chicken picking soloing, melody work, and rhythm.
It is also important to note that solid hybrid picking is important to capturing the "chicken picking" essence. I recommend using a pick between the thumb and first finger on the right hand to play the low notes along with a palm mute and grabbing the higher notes with the middle finger. This lesson isn't really difficult but the picking rhythm and shear number of patterns to memorize can be tricky. I suggest really taking it section by section. Enjoy!