Here's the albedo overview of the scene in Ue4.

Started by adding a sky sphere and a volumetric fog with very low emissive value.

Then added a skylight with an HDRI texture, As you can see the ground looks okay but the foliage assets are too dark.

To mitigate this issue I increased the min occlusion value to 0.22, but it's still too dark.

adding a directional light seemed to fix the foliage but it ruined the overcast effect I was going for since it create distinct borders between lit and dark areas, Disabling the directional light for all assets except foliage seemed to work,

Used light channels to isolate the effect of the directional light to the foliage only.

Adding a few spot lights to certain areas of interest.

Enabled planer reflections to get more control over the reflections in the water puddle.

Now that most of the lighting is set up I moved on to post processing, After experimenting with different values I found that Decreasing the saturation and increasing the gamma for the shadows improved the overall look of the scene.

Minor global gain and saturation adjustments.

And that's it, time to render the scene and export.