Like the previous poster, something that helped me was to eliminate the junk I have in the house. I have a bowl of fruit on the table because I'd much rather snack on a kiwi or a clementine than a bag of chips.
I also make the decision to figure out if I really am hungry or not. Today I didn't have to work so I was stuck in the house since it snowed all day, in this event I usually want to snack all day. So instead when I thought I wanted something to eat I would give myself 30 minutes. I would get on the internet or watch a show on netflix, whatever, but after 30 minutes was up, if I was still hungry I ate. If not, well then I wasn't really hungry right!?