First up, enjoy what you eat, but make sure it's the right size. A little bag of chips or a petite snack bar is fine if you know what to pair it with.
Always have a wee bit of protein with your snack. Carbohydrates are good immediate fuel, but protein has staying power, so combining the two is your best bet.
Don't eat what you don't want. If your body says nuts and you go for the apple, you could set yourself up for failure later on in the day. An apple with some nut butter could be a nice compromise.
Steer clear of drinking your snack. Smoothies to coffee drinks, liquids empty faster than solids, so hunger is quicker to return, no matter what the calorie content.
While 100-calorie packs help keep you honest, building your own can be cheaper and healthier in the long run.
A baggy of your favorite whole-gain cereal, dried cherries or cranberries and walnuts offers interesting taste and texture in small doses.
Go for a healthy fat combo. Olives have a good mouth feel and the ability to satisfy a salty craving, with a smattering of monounsaturated fat, or a quarter-cup of hummus and sliced veggies and whole-grain chips.
Edamame is becoming more and more popular, a near-perfect food as this bean comes with a nice trio of fat, carbohydrate and protein all in one pod.
What we're looking for is protein, healthy fats and fibrous carbohydrates to the tune of about 150 calories. If you're going for about 300 calories or more, that's considered a mini-meal, which is not suggested.