Appetite

I make sure to fill my calorie allotment with foods that are more filling on those days. For me, this means cutting out fruits except for bananas (not sure why, but there's a small population of people who get hungier after eating fibrous fruits like apples and peaches); and eating more lean protein. I also curb my carbs just a bit so I have more room for higher-protein foods.

On a typical day, for dinner, I might eat:

1 peach/nectarine/apple, or a serving of strawberries
150 grams of rice
3 oz of chicken breast
1 ice cream treat

On one of those high-appetite days, I might eat:

40 grams of nuts
60 grams of rice
9 oz of chicken breast
2 cheese sticks

I'm not being exact here, but it's roughly the same calorie count.

ETA: There's nothing wrong with going a little over on your calorie count on some days either - as long as you balance it out somehow. There are days when I have a very weak appetite and I'll end up a little low. These balance out days when my calorie allotment just isn't enough and I need a little more. Most veteran MFP posters seem to go by the week's average instead of judging every individual day as pass/fail; I've started doing this too and it's been working.

I'm gonna be honest, if I'm hungry, I eat. Most days I am in a calorie deficit. I'd say 6 out of 7 I'm usually under my goal, so if I get hungry, I'll eat a tuna sandwich or tomato sandwich, it doesn't blow my diet out of the water and it's just enough to squelch the hunger pain.

Eat a little less when you're not hungry, eat a little more when you are. I base my calorie goal on the weekly average, it works for me as my appetite varied as well.