Stewey is right propergomper. Pinching your nose and blowing gently into it is called the Valsalva Manoeuvre, and it works.
Whatever other people do, NEVER EVER EVER put anything in your ear. It's really dangerous.
Why? ...
The pain you feel is caused by the plane descending from low pressure air (in the sky) to higher pressure (nearer the ground). The cabin pressure increases, and presses into your ears. Doing what Stewey suggests will push air up it your ears (don't worry about the technicalities - just try it). This makes the pressure inside your ear the same as it is on the outside. Hey presto, no pain.
BUT ...
If you put in an earplug, the pressure between your ear and the plug stays at low pressure. So no pain UNTIL ... somehow, sometime, that pressure has got to come up to the outside pressure (unless you keep the earplugs in for ever). And when it does, it's gonna happen all at once. AND THAT IS GONNA HURT !!!
What's worse, the outside air pressure can force the earplug into your ear, and then you could be talking damaged eardrum.
So suck, yawn, pinch, blow, anything BUT ... DO NOT PUT THOSE DODGY PLUGS IN YOUR EARS !!!!!!!!!!