After completing our patio, we didn’t know what to do with the stray remnants of concrete pavers that were left over from cutting all the odd shapes. Rather than throw them away, we decided to use them to edge a gravel path in our large perennial bed. All the paver pieces had a flat edge, so we kept that edge up and buried the irregular sides, leaving 1 to 2 inches sticking out of the ground to hold the gravel in place.
Recycling paving fragments in this way can work with any material, including brick and stone. It’s also good design: Using the same material in different areas helps unify the look of a garden.