Eating at night has always been a problem for me, too.
I try not to eat dinner too early.
I keep sugar free Jello and sugar free pudding on hand and have that with a dab of whipped topping (because my weekness is sweets).
I brush my teeth. I won't eat anything after I brush my teeth.
I have also just changed my mindset about evening munching. That has not been easy but having the Jello or pudding to look forward to really helps.