Hold your nose closed, close your mouth and sloooowly blow, increasing the pressure. Your ears will pop and your pain is gone. Don't use a sharp blow since this could cause discomfort. If one ear pops before the other one, hold the popped ear closed. Even if your ears don't pop, you should feel the pain disappear almost immediately. Start the procedure early during the descent (before the pain appears) and repeat as often as required. You will soon get the hang of and I'll bet that you will never experience discomfort again.
Cheers,
Jerry B.