It isn't how you equalize, but when. While looking up tends to stretch the euatachian tubes as Net doc said, every diver has his own personal voodoo spin that works for him. So experiment until you find your own secret formula.
Meanwhile the problem that most divers have is that they wait too long. Once there's a pressure differential corresponding to about 6 to 9' feet of depth clearing becomes extremely difficult, if not impossible.
Imagine drinking a very thick milk shake through a straw. (If it's been a long time since you were a kid, go out and buy one) You suck gently and get a drink, no problem. Get a bit greedy and suck too hard and the bottom of the straw clogs, then the outside pressure collapses the straw. From here on the harder you draw the worse it gets. As any experienced kid can tell you, the secret is to blow down, clearing the bottom of the straw then suck gently.
Same for clearing your ears; if the pressure differential is small they'll clear fairly easily with any number of techniques, but descend too far and the external pressure flattens the eustachian tubes leading to rough or no clearing. Go up to reduce the pressure differential and the tubes will open again.
The simple secret is clear fast and descend slow. If you can't clear fast enough, descend slower.