Love what you eat. In other words, do not eat just "anything" or eat because you see it. Think about what will taste good to you and then go find it.
Watch the portion size. Many packaged snacks claim to be 100 calories per serving - but there might be 2 servings in a package.
Try whole foods. Never tried a mango? Well, this is a great way to kick the cookie habit. Try something that is sweet that is made by a farmer instead of something sweet that is made by Hostess.
When you are hungry and you are stuck in a convenience store go for the nuts. Packaged nuts give you great nutrition for the calories as opposed to Doritos, which give you nothing for the calories.
Cook. Yes, make yourself some food and then your enjoyment (see #1) will be increased. A homemade cookie tastes soooo much better than Chips Ahoy. Your home will smell good and you get much more nutritional value out of a homemade cookie made with butter and eggs.
Don't eat because you are bored, eat because you are hungry. So many times, we find ourselves eating because we want to stay awake, or just for something to do. Avoid this impulse. If you are bored, plan a vacation.
If you are looking for comfort food, eat healthy comfort foods. A bowl of soup is much more nutritious than a bowl of ice cream and it will fill the same need. Soup is very comforting.
Pack a snack to take with you. Know you are going to be tempted by the vending machine? Resist with a great snack that you put in your purse or briefcase. You will save money, time and calories.
Snacks that call themselves healthy probably aren't. Food marketers want to sell food and they will do anything to sell it. For example, "All Natural" could be used on Twinkies if Hostess wanted to put it there. Keep in mind an apple isn't packaged but it is a very healthy snack.
When you want a treat, get a treat. Don't get too obsessed with treats, just have them and love them.