For my dd, we use Sudafed (she can't take Benadryl), Earplanes, and a lollipop to suck on. Ideally, I get her one of those pops that look like a pacifier. If her ears hurt, I have Tylenol ready to go when we land.
My ds doesn't have any problems with flying, but he gets the same treatment as a precaution.
I have had major pain while flying. It's not just my ears--my whole jaw hurts. I do all of the above, with a nasal spray 30 minutes before take off and a Tootsie Pop (if liquids aren't allowed) or a water bottle (if liquids are allowed). I also take Tylonel if I need it when we land.
It's funny--I had a really good flight to MCO in Sept. In fact, it was the best flight of my life. There was a little discomfort, but not the pain. I was SO HAPPY! And, my ears were not even clogged for long. Coming home, I took all of the same precautions and I had a horrible flight. I was near tears in pain, and my ears were clogged for a couple of days. It must vary due to individual cabin pressure.
I hope your flight is good.