If you are one that drinks alot of soda, if you cut out all soda and drink a galon of water a day, you will probably drop 10-15 pounds (depending on your current size) just by doing this. I drink about a case of diet coke a day. I once stopped and replaced it with water. I dropped 15 pounds in a month, easily.
Everything else is common sense. As mentioned, portions are the thing most people overlook. I recently started getting my meals prepared by a chef "Sounds fancy huh?" but, it is affodable (about $25.00 per meal, and that is a meal for 6 people). Each meal is portioned... so although they say 6 people, if you eat 3 portions as a meal for yourself, well then that 25.00 meal is only going to feed two people.
http://cenatogo.com/
Thats the place I use. They have a new menu each month, you order your meals for the full month, they prep them, you pick them up, freeze them (Cause it's all prepared fresh, not processed), and there you have dinner every night of the week. Healthy, portioned, and about 350-500 calories per meal.
I'm sure there are other services of this nature around... you just need to do some homework...