Floating weightlessly with only two chords

Here's a technique popular with composers of ambient music, film soundtracks, and symphonic music. You oscillate slowly back and forth between two chords to create a sense of movement without direction. It's simple, yet unsettling.

To make this the most effective, pick two chords that have absolutely nothing to do with each other. Here are a few examples:

E - C - E - C -
Fm - D - Fm - D -
Ebm⁷ - Gm⁷ - Ebm⁷ - Gm⁷ -

For the ultimate floaty effect, pick two seventh chords half an octave apart. These chords are tonally as far removed from each other as any two chords can be -- yet, paradoxically, they share two out of four notes in common. It's like moving to the opposite end of the room while standing perfectly still. Spooky!

G⁷ - D♭⁷ - G⁷ - D♭⁷ -