Keep swallowing. It opens up the passage and equalises the pressure either side of your eardrum. Fortunately I can do that at will, never quite sure why we all can't :-)
Actually, if you pierce both eardrums that might do it !
Boiled sweets, sucked hard all the way through takeoff. Does it hurt when you're actually in the air at altitude, too? If so you might need to see the doc. OH had dreadful headaches at altitude, he had to have an op on his sinus to relieve the pressure - not sure if there is an equivalent for ears....
The problem will be on descent rather than anywhere else, so go to the chemist and buy any nasal decongestant spray and spray both sides of the nose about 20 mins before descent.
Sqad's advice is probably the best... however, if your ears are blocked on descent, hold your nose and swallow... never blow. Reason being is the Eustachian tumes run downward from the middle ear to the back of the throat... blowing only forces the mucus/blockage back up the spaghetti thin tube.
As one site states: "...When you swallow or yawn, the tubes open briefly to let air in to make the pressure in the middle ears equal to the pressure outside of the ears..."
The only caveat with the decongestant... don't use it for more than 3 or 4 days consecutively. To do so risks the "rebound" effect. The onset of congestion re-occurs ar a shorter and shorter time with overuse. Most pilots I know use a corticosteroid nasal spray decongestant which eliminates the rebound effect, but it's expensive and requires a doctors prescription. I use Beconase, since it only requires on spray in 24 hours...
Years ago, I experienced it spades, Sqad. Using a non-steroid product called Afrin, I had a persistent cold and associated congestion and Afrin had just come on the market. Ah... the relief in just seconds after using it... I could actually breath through my nose. However, I hadn't been warned of the "rebound phenomena"... and about a week later, I could still get relief after spraying, but it would only last 10 or 15 minutes...
Yes....you are probably correct Clanad, but i have always felt that this side effect was overstated as i have only seen a dozen cases in a lifetime of practice.
This brings back memories of my first visit to the USA .
My ears popped as we were descending and long after landing, still a bit disorientated , with the echoey feeling in my ears ( like one gets when under water ).
So i am in a strange country - it's getting dark - i am in a left hand drive hire car and have to drive from airport to hotel .
I always used to suffer from this and the pain was terrible. I now use Earplanes earplugs. Put them in just before take-off and remove them when you are in flight. Put them back in just before the descent for landing and remove before you get off the plane. I tried all the other suggestions that have been made and is the only solution for me, works every time I fly :) Get them in Boots and I think Amazon sell them too!