As most divers know, equalizing early and often will prevent problems and "squeezes". If you wait to equalize until you experience discomfort, then you have waited too long. You should be equalizing - gently - as often as possible on your descent. Some agencies teach that one should equalize every meter / 3 feet or so. Personally I think that one should equalize a lot more often than that.
The key issue is that the pressure change is huge in the first 10 meters / 33 feet of the dive (I will not delve into the theory now, but will do so in a later post). Therefore the pressure difference in the inner and outer can be substantial, even at relatively shallow depths. It is critical that you equalize the pressures before injury occurs to the delicate structures in your ear.
Please see this excellent tutorial by Edmond Kay, M.D. for more indepth information on equalization techniques and theory.