A technique that is used in conjunction with open string slurring, is the fretting of the open string with the right hand. The following photograph illustrates how this is done.
In this photo the middle finger of the right hand is pressing behind the third fret.
In this example you can pick the first note or start with a hammer on. This riff is played using notes in Pattern 1 at the seventh position.
The right hand can fret any note between the nut and the left hand, so you should experiment with other combinations. Practice this technique in other positions on the fretboard and play them against other chord progressions.