Create a pattern using the straight harp technique. Create the melody line of songs using individual notes when you use the straight harp. You can vary the song by using other harmonica techniques that you pick up in lessons in the song.
Use harmonics in the second position when you use the cross harp technique. The cross harp tends to be used more when you play more for bluesy songs. It has a much fuller sound than the straight harp because of the chording. You draw in on the lower end when you use the technique.
Combine the chords with individual notes to play an interesting composition. When you take harmonica lessons of the song the instructor gives you use both in combination for variety.
Bend the notes in the song. If you took harmonica lessons the instructor would teach you this simple technique. You can bend a note by changing the shape of the air flow. Say "wheeeeooooooo" with the harmonica in your mouth. The sound of the note changes when you get to the "ooooo." That's bending the note.
Vary the articulation of the notes in the song. Use your tongue to create staccato notes. Vary the length of the notes and the way it stops when you play different songs.
Insert various phrasing that you hadn't used before. A simple harmonica technique that you don't need lessons for is phrasing. The phrasing varies by when you take breaths. In this case when you inhale into the harmonica a totally different sound comes out and the change in the tone can change the composition.
Cup your hands around the harmonica to mute the tone. Create different sizes of cupping and different patterns to the cupping to add a lot to your harmonica technique.