Riding the clutch is when you rest your left foot on the clutch pedal while driving, partially depressing it. This will help to wear the clutch out prematurely. It often occurs without the driver realising they are doing it, so to avoid this you should remove your foot from over the clutch pedal after you have finished accelerating and changing into the lower gears so as to avoid temptation of resting it on the clutch pedal. Learn to do this without thinking about it as soon as you are comfortably travelling at your desired cruising speed.