There are probably some good ideas in the Nutrition/Recipes section of the forum.
My snacks tend to be easy to grab - carrots, celery, mushrooms, sugar snap peas, wholegrain crackers, a glass of milk or unsweetened tomato juice, vegetable soup, occasionally almonds (if I think I haven't eaten enough), lowfat diet yoghurt, fruit.
My usual lunch is wholemeal crackers - not usually Jatz/Ritz cause they have more fat in them. I buy the ones you snap into little squares. and eat 8 squares rather than 2 slices of bread. It seems like more food to me this way. Then I top them with lowfat cottage cheese, a little low fat hard cheese, or a small tin of tuna, plus a sliced tomato. If I am trying extra hard to make them appealing, I make them into little towers, with little pieces of other veges - slices of mushroom, cucumber, capsicum, olive maybe. If I'm feeling hungry I have extra veges - like the snacks above. Usually I have a small piece of fruit too.