Explanations:
Heel and toe: using heel of our foot to blip the throttle to rev match the engine to transmission speed when going into a corner. Toes are on the brake pedal, left foot is on the clutch. Right foot operating brake and gas at the same time just like they teach you at the DMV.
Double clutch example: going from 1-2, you press clutch, go to neutral, let out the clutch, press the clutch back in, go to second, let off the clutch. Each up shift requires 2 press and releases of the clutch pedal.
Skip shift: you accelerate hard at times in one gear, and then since your speed is high, you skip a gear and go either 2 or 3 up. This is very very bad on your synchros but few people are actually aware of this. If you do it or have done it, please vote. I'd like to know how many people are unaware this is a bad practice.