Whenever possible during the day, try to eat with soft light and soothing, relaxing music on a low volume in the background. The music especially helps to calm me, slow me down, which in turns helps to chew more, feel full sooner, and finally to eat less. I have also found instrumental music seems to calm and relax me most.
I usually have it on in the living while I am eating in the dining room. Try it, you just may find it helps you, too!