Biggest error most people make when landing the 172, especially with no back seaters, is not flaring enough. Watch at any GA field - loads of 3-point landings. That leads to bounces becuase the aeroplane still has airspeed and will rebound into the air and continue to fly.
With power off it takes a mighty pull to get that nose up to hold off before touch down. Leaving a trickle of power on helps, as it makes the elevator more effective.