Here are some ideas:
1. Start with two cups of jut about any vegetable or combination of veggies. This could be a salad mix, steamed asparagus or broccoli, dice cucumbers, steamed cauliflower "rice"--the list goes on and on and on. The key here is that two cups of any veggie will fill you up and probably only has 25 calories. This should be the basis for both lunch and dinner and any snacks you eat.
2. Limit your protein portions to 3-4 ounces per meal. That might be two eggs, or half a can of tuna, or a palm-sized piece of beef, chicken, fish, etc. The easiest way to prepare your meat is to grill or broil, but you can certainly do a roast or bake chicken if you want.
3. Cut WAY back on starches like bread, pasta, cereal, rice, potatoes, and corn. Also cut back on dairy.
4. Use good fats intelligently. You can't put a cup of dressing your salad, but you can put a couple of tablespoons or use a little butter or mayo or pesto sauce. Fat not only makes foods taste better, they will give you more satisfaction that a pile of noodles.
5. Drink lots of water.
6. Eat slowly and wait. It is common when we eat, particularly if we eat quickly, to feel that we are still hungry. It takes about 20 minutes for your to feel full. So, eat your calorie and portion controlled meal and then stop eating. Drink some water or decaf tea. Do something else. You will discover that you aren't actually starving and don't need to eat more.