On final approach increase airspeed, though opposite "the first rule", your approach speed is well below your recommended turbulence speed.

When flying over rolling hills and experiencing mechanical turbulence, climb to a higher altitude.

Remember hazardous turbulence in unstable air generally does not extend a great distance downwind from the barrier.

While experiencing turbulence of any kind: reduce airspeed to airspeed recommended in your POH, keep a steady altitude without over-controlling (ride the waves), and constantly watch your instruments.

During Pre-flight gather as much information as possible: Cloud reports, Wind direction, Wind speed, and air stability.

Remember wind at the mountain top in excess of 25 knots suggests some turbulence. Wind greater than 40 knots means use extreme caution. 

When approaching mountains from the leeward side during strong winds, begin your climb well away from the mountains. 

Climb to 3000 ft AGL - 5000 ft AGL above mountain tops

Approach at a 45° angle