The trick to the partial chords sounding good is finesse. Play around with the amount of bend and the ratio of sound between the two notes until it sounds like a favorite blues player or until you're happy with it. The tongue blocking technique of playing single notes allows you to add some great new chord sounds to your playing. Please note that the partial chords technique described directly above will also work well with tongue blocking. Octaves Using octaves - An aspect of the tongue blocking technique which allows you to play an 'octave' by covering four holes with your mouth and blocking the two middle holes with the tip of your tongue.
Octaves are great for adding fullness to the higher melody note.
True chords will generally have 3 or more notes in them, but an octave can be considered another type of partial chord. The high blow and draw octaves are not used much because they don't have the same full sound that the lower octaves do. What you end up with is an interval of a flatted seventh which is very bluesy sounding. Paul Butterfield is one of the many players who utilized this sound frequently. Experiment with combinations to see what you like.