The lighting example at the very start of this is way better than the one at the end, but the fundamental principles are the same throughout. This went way long, woops.
a quick disclaimer, I am NOT a trained artist. I have however , been taught basic things by trained artists. there are still FAR better sources for lighting information out there, so take it upon yourself to go out and learn, Lighting is one of the most important parts of high production value filmmaking, and in source filmmaker, you have all the tools to do it at top quality if you just take the time to learn. Heres a quick link to get you started