1. Are you using a HDRI skybox? Or the standard lighting that comes out of the metaphorical box with Enscape?? Get a good HDRI during sunset or morning. You won't be able to change the time of the scene via the normal shift + right click hold and drag.
You'll have to adjust sunlight angle manually via the rotation option, and intensity of sun / stars and moon. I find starting at a low sun intensity or even at 0 and then working up to desired effect is most useful.
However, don't depend solely on this to light your scene, just use it to set the ambiance. Utilize the exposure controls to adjust overall brightness after figuring out your sunlight etc.
Also couple this with step 2 to enhance dark areas that just aren't covered in sunlight or exposure.
2. Make sure you utilize emissive lighting for interior lights ie transparent light bulb , as well the usual point box or spotlight. You can also use a rectangular plane wifh emmisive properties to light a scene like a soft box. It will shown up in reflections however, so I usually only use it with little to no glass around. You can also control emissive brightness by alt+left clicking the material with the paint bucket tool, and adjusting the luminance slider in the material editor.
3. Try to break up then light entering the scene. Put a couple trees or plants outside an exterior window, add some shadow to the interior scene. Really helps improve the overall ambience and can really add more depth to complex textures. See my post in "material realism test" under the showcase topic and scroll down until you reach the concrete and wood corridor. I varied tree height and rotation outside all exterior windows to give me some soft shadows and it made the scene.
Let me know if that helps - I was planning on starting a tutorial / walkthrough series on YouTube if I have the time. There's a bunch of other things, but see how that works out for you.