Whenever possible, climb above the cumulus layer and enjoy the ride. Since we know turbulence is created by wind swirls and eddies, this type of turbulence is the easiest to imagine. Obstructions such as buildings, trees or rough terrain can make a mess out of a previously smooth airflow. The disturbed air can stretch miles downwind of the obstructions and the intensity varies directly with the force of the wind. This mechanical turbulence can often be identified by a layer of stratocumulus clouds in neat, little rows or bands, parallel or perpendicular to the wind direction.
Clouds created by convective currents tend to form in very random patterns.
Mechanical turbulence over mountains can generate turbulence much higher than the mountains themselves. Air spilling down onto the leeward side creates downdrafts, sometimes at speeds in excess of the maximum climb rate of your airplane. The good news is the associated disturbances frequently don't extend any great distance downwind from the barrier. Stay out of the yellow arc. Always wear your seatbelt snugly, and take a minute to secure anything loose in the cabin before entering rough air.