If you have been doing it by feel so far and you have hit a plateau, it's time to start counting calories. Understand what your caloric maintenance is and how much you are expending during training. You need to create a negative energy balance.
The best approach is to cut your calories by 10-15%. The benefit of doing this is that it will allow you to retain the majority of your lean muscle mass while you are dropping the body fat. The downside is that there is little room for error. If you cut more than 15% you start getting into the moderate deficit area and you really have to watch your quality of food and macro nutrient ratios (this is what people mean when they say a calorie is not necessarily a calorie...but you do need to be in a deficit to drop body fat as you can't defy thermodynamics).
Google fitness professionals like Tom Venuto, Lyle McDonald, Alan Cosgrove and Leigh Peele. They have lots of excellent articles and insights as how nutrition and training relates to body mass and fat loss.
Good Luck
