Calorie counting - for calculations you need to know that 1 gram of protein or carbs has 4 calories and 1 gram of fat has 9 calories. And of those calories, they need to minimize the saturated fats, and maximize the proteins and carbs.

Keep a Diary, whether it's an online version or written down. It will make you more aware of what you are eating, and of course which foods are better or worse for you.
I did use MyFitnessPal, and it was a good guide for your daily nutrients. More recently, I have used Zoe. Which is also very educational aswell as target driven logging system.

My rule is to always choose foods that are as close to their natural state as possible. Eat the whole egg, not just the white. Choose full-fat organic dairy over low-fat, antibiotic-ridden dairy. Include a small amount of nature’s fats (organic meat, avocado, oils, nuts and seeds) in your diet rather than opting for the packaged foods.
They may be low in fat, but they are typically high in sugar, synthetic chemicals, and heavens knows what else.

Calories don’t count.

Your body is perfectly capable of doing whatever it wants with the foods you eat. I’ve seen people gain weight and feel awful on a low-cal diet while others regularly indulge in meat, (good) fats, and a daily feast of vegetables, seeds, full-fat dairy, and nuts. It’s all about listening to your body which is tough to do if your mind is overwhelmed with sugar and chemicals from all that low-fat food.

Include Protein.

Protein-based foods are the building blocks of a healthy diet and protein has several important roles in your body. The list includes cell repair, cell regeneration, hormone production, and blood sugar management. In fact, pretty much every different diet, while possibly excluding carbohydrate or fat, recommends some form of protein. This alone should indicate how important it is.

In my experience, most people do not eat enough protein. If you think some chicken breast in your evening stir-fry or a slice of ham in your lunch focaccia is going to cut it, think again. I’m talking quality protein at all 3 main meals and possibly in between, depending on your level of activity. Your main sources of protein should be from natural sources such as dairy, eggs, poultry, meat, and fish. Legumes, nuts, and seeds also provide some protein.

Aim for 0.8 grams of Protein per kg of body weight. Body builders could go to 1 gram per kg of body weight.

Be smart about Fat.

If you’ve heard of Omega 3, then you’re already onto the benefits of smart or good fats. The most commonly known smart fats are the essential fatty acids Omega 3 (O3) and Omega 6 (O6). It’s crucial that you include these fats in your diet as your body is not able to produce them and they are critical to your health. Good fats serve many wonderful purposes, including the reduction of inflammation, improved detoxification, and they’ve also been linked to weight loss.

The typical Western diet tends to emphasize O6, through over-consumption of vegetable oils such as corn oil, sunflower oil, and safflower oil. Corn oil in particular, is used in most baked and processed foods. A healthy diet should include an O6:O3 ratio of anywhere between 1:1 and 1:4, so it’s crucial that you take steps to increase your Omega3 intake. You can easily do this by including eggs, walnuts, oily fish, flax seeds, leafy greens, and a good (mercury-free) O3 supplement. In nature, you would eat up to 40 grams of O3 each day. considering that a heart salmon steak only has around 7 grams of O3, I’d say that supplementation is a good option for everybody!

Eat when you’re hungry but not before.

It’s popular for modern-day diets to recommend that you eat small meals at regular intervals throughout the day. This approach has taken off as it’s said to regulate blood sugar levels and ensure you don’t give in to the temptation that can come about when hunger’s a-gnawing. While this is a good approach for many people, it’s not necessarily the right one for you. The truth is that some people do need to eat 5 or 6 or even more small meals each day.

Quality counts.

It stands to reason that a diet rich in nature’s rich foods is one with a focus on quality. Unfortunately, the typical supermarket products are often produced as efficiently (cheaply) as possible. That’s why you pay the price with your health. There’s a tremendous difference, for example, in the health-giving benefits of a caged egg (which has an O6:O3 ratio of around 20:1) compared with an organic egg (which has ideal O6:O3 ratios). According to many health experts, supermarket fruits and vegetables are mostly covered with dyes, waxes, and even fresh smells in order to trick you into believing they’re fresh.