For me it's helpful just to do three meals and absolutely not eat any other time. I try to wait until 7:00 a.m. to eat breakfast and I keep it under 600 calories. I can't have lunch until noon and still keep it under 600 calories. Ditto dinner which I do not allow myself to start preparing until after 5:00 p.m.
If I have to have a snack between meals it is not allowed to take my last dinner total over 600 (so if I only ate 500 calories for lunch, then I can have a snack at 3:00 p.m. that's under 100 calories).
Keeping carrot chips or pepper rings or dill pickles around to munch on if I'm really hungry helps. At night my "snack" is usually just decaf coffee or tea. I've lost 59 pounds in just under 3 months (300 lbs to 241 lbs). So far it's worked for me.