This is probably my #1 https://en.wikipedia.org/wiki/Crispbread Either plain or with low calorie butter
Good suggestions for snacks but I think a lot of people missed the "when I want to shove something in my face as a force of habit." You really want to get the lowest calorie thing possible, ideal would be lettuce and celery since those are basically nothing but still give you something to eat. Next would probably be apple slices, berries have surprisingly low sugar, egg white is basically pure protein but a full egg is fine too. Sprouts can be good if you grow them right. I sometimes just slowly eat a spoonful of peanut butter over like an hour but...
I would also recommend having random drinks you can go between, like tea soymilk coffee, even diet soda. Just avoid anything with sugar or fat. Things like nuts are healthy but not a great constant snack food because they do have a lot of fat, so that should be an intentional thing rather than something to reach for.
