Watch the 1/2 Step Slide Embellishments online guitar lesson by TrueFire from Play Acoustic Guitar 5: Fingerstyle Principles
1/2 Step Slide Embellishments - Concept 5 is a video guitar lesson presented by Brooks Robertson and is sourced from Fingerstyle Survival Guide.
This is a great sounding tool that you can use for a variety of different sounds. It will be important to have a grasp of some basic chord forms that you will apply this technique to. The primary idea is to take any chord form and play the chord in double stops (groups of two notes at a time) ascending or descending. What gives the technique an even more unique sound is adding in two slides (down a 1/2 step, then back up to the cord tones) after initially playing the double stop.
After some experimenting you might find that this would also work with groups or three notes, or four, etc.. First practice the technique with very few chord forms, even one is enough to begin. Then as you become more comfortable, smooth and fluid with the concept try it with various qualities, inversions and progressions of chords. It is up to you to experiment with all the various songs and places you could apply this technique and what sounds good to your ears.