Watch the Voice Leading online guitar lesson by Mimi Fox from Flying Solo
Here I am playing the melody on top of the chord and using the two highest strings to voice lead. A great way to begin doing this is to simply play the appropriate scale up and down the neck on the two high strings and then add the chords for each note. If you are starting with a Bb7 chord, use the Bb mixolydian scale. Then use the Eb mixolydian scale for the Eb7th chord and continue on in this fashion through an entire 12 bar blues in this fashion; choosing the correct scale for each chord, and then putting a chord to each note.