The difference in cabin pressures is controlled by the Captain and when he decides to pressurize the cabin and then depressurize when descending. Normally, I would pressurize the cabin as we were being pushed back from the gate, while some Captains would wait until they were cleared for takeoff and other Captains would wait until they actually began their climb, but always before hitting 10,000 ft. altitude. It's also important to note the size of the plane. Larger planes control pressurization better than the smaller jets. When descending, the angle of attack and the attitude of the plane are important for the Captain to be aware of and when it is safe for him to depressurize the cabin. Again, my choice was normally when we touched down. There are instances when a pilot may have to perform what we call a "TOGA", which stands for "Takeoff and Go Around." If the pilot would short the runway, meaning that he landed too far down the strip and would not or may not get stopped safely, he may have to fully accelerate the jet and get the plane back in the air to perform a go around and try landing again. Normally, this should only happen to First Officers who are still getting their feet wet with real aircraft and not being in a simulator.
As for ears popping while descending, it's again up to the pilot. If he has a steep angle, ears will pop more frequently that they would if the angle of descent was less steep. Normally, a 5% angle is normal for descending and taking off, unless the pilot is under a "noise abatement" order. Like, if the airport was located near a housing development, the pilot may have to take off using a greater angle of attack, like 8-10% while being careful not to have a tail strike on the runway.
My best guess is that the airline that you fly with uses a shorter angle of attack for both taking off and descending. It is important that the passengers have their ears pop. This relieves the pressure in the Eustachian tubes or canal, which causes the pain. There are a lot of aids out there in drug stores to help with this problem. Normally, I just prefer to yawn. For others, they may need to take more drastic measures like using medication or a special ear insert.
Planes have to ascend and descend gradually to prevent them from breaking apart. However, there are times when the pilot will need to use a greater angle of attack while performing these duties. Babies are more effected by pressurization than adults because their inner ear and it's tubes have not yet been formed or strengthened properly like an adult's ear has. Some people are completely unaffected by pressure in the plane while others will complain almost the moment the plane begins to ascend.