I find that when I start snacking on something I want to keep eating it. So I try to dole out the portion size on the back of the package (or use common sense for non packaged foods) and then when I am done with the serving, brush my teeth. That takes the taste out and the need to keep feeding.
I also find that if I skimp on breakfast lunch or dinner I am snacking later. There no point in eating a salad for lunch if I'm just going to eat a whole bag of Goldfish later on
! So I make sure to fill up at mealtime. (for instance I load my salad with meat, avocado, cheese, and maybe a handful of goldfish
I usually make a green smoothie at mid morning to get me to lunch, and then have a cup of chai tea with milk honey at 3ish to curb that mid afternoon sweet craving.