I have zero knowledge of lightning so I agree with all of you. As a total beginner about lightning I think the most important aspects would be theoretical. I didn’t know there was a system of three lights as @williamatics mentions.
I need to understant how light works in order to make the most of it. Of course, some artsy tips about what usually works would be awesome. But I’m confident I’d be able to tell a story, or place the focus where I want it, if I know how lightning works in order to tweak it to my liking.
@dostovel is right. I do have terrible renders because lightning eludes me. I can follow a tutorial step by step and achive something which is ok, but I’m unable to light something on my own and my last exercise submission would have imrpoved a lot if I knew better. So I second the motion of @ketre Yes to Lightning and Compositing!! 🙂