First and foremost, let's make this clear: it doesn't matter if you do thousands of abdominal exercises, if you don't tailor your diet for the appearance of lean muscle, you won't have that washboard stomach you want. This is one of the most important principles to getting muscle tone. The lower your body fat percentage is, the more defined and vascular you will appear. Eating take out three times a week will only derail you on the path to getting that muscle tone, no matter how hard you work in the gym.
2. How You Lift It
The next key to adding definition and tone to your physique is ensuring that you have the proper training principles in place for maximum results from your workout. High-intensity training is the way you should approach your workouts to get maximum definition. You should be performing exercises for two sets for approximately 18 to 20 repetitions for a weight you can manage those 18 to 20 times. You may also want to lift in a high-intensity circuit, completing one set of 12 to 15 repetitions sequentially with little rest in between. Complete a lap of 10 to 12 exercises, and repeat for two more laps. You should be training for strength at least two to three times per week. This principle is commonly known as a "low weight, high reps."
One of the most important parts--but the one that gets overlooked the most--to maintaining a good, toned physique is adequate cardiovascular training and conditioning. Performing enough cardiovascular training will help you maintain peak physical condition. Think of a prizefighter in boxing or mixed martial arts. They put in miles and miles of "roadwork," training their cardio endurance. Come fight time, they are some of the most well defined athletes on the planet. You may want to apply the same high-intensity principle to cardio training. Usain Bolt's physique is incredible, yet he is not known for his long-distance running training.
Applying these three simple principles to your workout in the new year will help in achieving your goal of a toned, defined physique.