Ok, some practical tips that don't require a life and pantry overhaul :)
Instead of eating chips or cookies out of the package, put a serving in a small bowl or plate (dessert sized, not dinner sized) and put the package away. This will keep you from accidentally eating more than you planned.
If you find yourself going back for seconds out of boredom, not hunger, brush your teeth after you finish the first serving. Even Oreos and Doritos taste like shit with a mouth full of mint!
You can also try asking for items that you don't particularly like. So, for example, even in my worst munchy mood, I could never overeat cool ranch Doritos, flaming hot cheetos, lemon flavored cookies, glazed donuts, etc. Because those are things I just don't like. I've never met anyone who likes ALL junk food. If you can only stomach a little salt and vinegar (my fave!) potato chips, ask for them over your regular ones. You might still eat some, but you won't eat the whole bag.
Set a timer. Studies show cravings usually only last for a few minutes, typically. When you get an overwhelming craving for, say, chocolate, set a timer for 10 minutes. If after 10 minutes you still feel like you HAVE to have that snack, go ahead and have a little bit. There are even apps for this.
Don't eat in front of the tv. Eat at the table or, if you don't have one, eat with the tv turned off at the very least. No mindless eating. Focus on the taste of all the food you eat. Chew it slowly. Think about how it smell, the texture, the color. A lot of overeating happens with foods we aren't really even enjoying, just putting mindlessly into our mouths. Take time to enjoy it and you'll probably find yourself eating less of it.
Lastly, whenever you feel hungry or strong cravings to snack you should try having a glass of water first and then waiting 15 minutes. It sounds crazy, but we sometimes misinterpret thirst for hunger. This happens to a lot of people. Drinking a glass of water and then waiting will help you decide of you really are hungry or if you were just thirsty.