Paleo seems to be popular around here but I am pretty skeptical of it actually being a good idea (I am open to updating if evidence is presented). Intermittent fasting is the only thing I really feel like I can recommend, and even that is something that will work for some people but not others (did not work for me, but LeanGains makes specific enough predictions that a sufficiently large number of people seem satisfied by that I am convinced it is a real phenomenon).

Also fixing any deficiencies you have (more water if you are dehydrated, for instance; probably more protein if you are a vegetarian).

A very simple and easy first step is cutting out all liquids except for water (if that is too difficult, start with the soda). This helps a lot.

If you're looking for a good diet, the first question is - a good diet for what?

I think there is a vague consensus that, all other things equal, eating less will make you lose weight and eating more will make you gain weight? I might have seen someone post a counterexample at least once, but I might simply be misremembering.

The consensus I've picked up is that if you focus on just eating the right macronutrients and getting some exercise, everything else usually works out - try to replace sugar, refined starch, and processed fruit/vegetable product with protein, lowish glycemic index starch, and less bland fruit/veg.

Another idea that was useful to me is that mass-produced food has to have a low water content, or else it goes bad really quickly, and so replacing water with fat is a great way to make mass-produced food better. But in fresh food there's no such limitation. This means that eating fresher food basically substitutes fat for water in a lot of your food items.

1. Make it difficult to consume more calories than the amount of calories necessary for maintaining your target weight. E.g., make it such that you need to eat a lot of food everyday to reach the maintenance level for your target weight (fast food, e.g., makes it very very easy to go over that target). Or you only eat after a certain time late in the day.

2. Religiously monitor your progress. Take pictures of your back, side, front every week. Weigh yourself everyday. Take measurements -- use us navy body fat calculator. Find a way to show off your progress. (This is all purely motivational.)

3. Do the kind of exercise that you will excel at with your desired body type. If you want to be muscular, do a lot of body weight exercises. If you want to be lean, do a lot of long distance running. But note that some body types require different nutritional compositions.

4. This must be a lifestyle change, and not a temporary thing to just lose fat.

5. You need to believe it will work, and continually adapt to setbacks.

eta: this is what I've gathered from the research showing the strategies of people successful at losing body fat and maintaining a lower bf%.