Hey Umbrafox,
A lot of getting correct lighting is about trial and error since there are some many different values and assets that can affect the overall look and feel of your scene. I would suggest taking a look at our ‘Architectural Visualization’ section on our Forums page. The threads within the section are all about creating a realistic type feel for their projects, and will definitely give you some solid insight on how to get started with lighting your project properly.
Architectural Visualization Forum Threads
https://forums.unrealengine.com/forumdisplay.php?63-Architectural-Visualization
I would also take a look at some of our sample projects that utilize BP_Skysphere blueprint, like the Landscape Mountains project. Let me know if you are still having trouble getting your lighting correct within your own project, or if you have any other questions.
Thank you,