Watch the Pickin' 3rds: Study 1 online guitar lesson by Jason Loughlin from Country Guitar Survival Guide: Lead Edition
The two most used intervals in country guitar are thirds and sixths. In fact it doesn't end at country guitar, these are the most commonly embellished intervals in popular music. This interval is the building block of harmony. The major and minor third shapes are the jumping off point for so many great licks. So it's important to have a handle on them. We are going to start with thirds and there are many ways to approach picking them. The interval of a third is the combination of two notes that are three scale steps apart. It may seem tedious to not lump them together with sixths but the level of command you will have when you come out of the other side will be immeasurable.
I'm sticking with one pattern in the right hand so you can concentrate on the different ways you can move thirds over the neck. In this instrumental study I'll be moving thirds through scales, targeting chord tones, adding chromatic passing tones and outlining chords.