Playing melodies as octaves is one of my favorite techniques. The clarity and emphasis carried by octaves is always striking.
When used in certain ways, octaves can also effectively carry a chord progression. In the video below, I outline some ways to choose octave notes that not only convey the chords, but also add a distinctive flavor.
For more on playing piano chords or going beyond chords to create melodies, check out the Fluent Piano courses here.