Guitarists
Compose from the guitar in your hands.
A riff, voicing, chord shape, or picked figure is already musical material. It does not need to pass through notation before it can lead somewhere.
Cadorin begins with the shapes and positions already under your hands. You might ask: How else could I play these changes? What could go over this? Where could this phrase go next? The answer is a musical possibility to work with, not a replacement for your judgment.
Guitar composition can move outward from the instrument: a figure into a progression, a progression into melodic territory, or a familiar shape into another register. See four ways to develop a riff.