there are several things you can try, here is what I do sometimes:
1. Make a cup of chamomile or your favorite tea (I prefer chamomile in the evening since it is relaxing and has no caffeine). Since it will be hot and take a while to drink, it should help take away those cravings. The fact that it is all water will fill you, the warmth will comfort you and it keeps your hands and mouth busy for a while. BTW, try not to add any milk, sugar or any calories to it or else you might be defeating your purpose.
2. 100 cal popcorn. A whole bowl of popcorn for 100 cals. Satisfies me when I really want to munch.
3. low calorie fruits. I tend to give myself free reign over how much I eat of fruit since it usually fills me well before I eat too much of it and since fruit is for the most part, lower calorie, I don't limit myself. I usually eat strawberries, blueberries, melon, and clementines. No, these are not all low cal fruits, but like I said, most fruit will always be a better option than even a low calorie processed snack. You get vitamins, water, fiber and it is sweet!
4. Asian sweets. Sounds weird, I know, but if you happen to have an Asian food store near you, check out their cookies and such. They are usually individually wrapped so you hold yourself accountable to only allowing one wrapper to get unwrapped. Many of the ones I really like are within 100-125cals each. It satisfies my chocolate sweet tooth. They're not very sweet, but just enough so. I might have one of these with my chamomile tea.
5. (my favorite one) A glass of low-fat milk. Not only will this fill and curb off your cravings, it is healthy and the protein (casein) in it is supposedly the best type for your body to utilize while you're sleeping.
As far as figuring out the cause of your cravings, that would probably be the most beneficial. My husband and I like to watch our shows after the baby is asleep, so lately we've been sneaking out our show snacks then. This had turned into a terrible habit that we now associate with enjoying our shows. I started drinking a glass of milk right before I put my daughter down for bed so that my stomach was content earlier and then I could sip on tea while watching our shows. It helps to really try and get to the root of your habits to find an effective way to deal. If you also are associating your evening routine to eating, try to do something different to break your habit. Instead of watching your shows, set your DVR if you have it, and go for a 20-30 minute walk.
Hope some of this helps,
L