Now ofcourse im not so dumb that i Think there is some secret button for this, but what is it i need to focus on to get good lighting? Is it the Directlight thing or the Skylight or the Postprocesing?
In short, the way to get your lighting correct is to use a combination of the three features you mentioned. Direct lighting, Sky lighting, and Post-Processing. My first suggestion would be to disable the ‘Auto-Exposure’ feature within the post processing settings. Then decide whether you want to sacrifice a little performance for quality by moving to a ‘Movable’ Directional Light and a ‘Movable’ Skylight. These mobility types provide the highest visual quality and mutability.
Post processing is your friend, but if used too extremely, can be your downfall. It is all a balancing act between lighting and post processing. Looking at your image, you will want to add some height changes in your landscape to give it a more organic feel as well.
Your best option would be to take a look at our documentation on Lighting the Environment to get a better understanding and knowledge of how lighting can be optimized to get the desired look and feel for your scene.