You've have mastered the elements of composition, then you were told by a contemporary or some rando on YouTube that lighting was everything. You watched tons of YouTube videos, practiced, and possibly even dumped a small fortune into all the myriad tutorials you've seen advertised everywhere. However, something is still missing. What could it be?
Probably two things: You're location and your set design.
I contemplated this a while back when I saw a video by Danny Gevirtz:
https://www.youtube.com/watch?v=8TijQqFEY3I
In the video, Danny was talking about shooting in harsh light, but one of the commenters mentioned that one of Danny's talents that he hadn't mentioned in the video was picking interesting locations. So many videos on YouTube focus so much on lighting and pedaling lights, that I noticed relatively few cinematographers or YouTubers focus on setting.
You can have all the lighting tools in the world and know all the angles and tricks, but your shots can still come out very boring. Try as often as possible to find a location that is interesting. If this isn't possible. Try to do some set dressing.
In this shot, the room was very interesting, but it needed to be a night scene. I strung a bunch of Christmas lights across the background for visual interest. I knew I could create some interesting bokeh because the room was so large, and the lights were a good distance from where I was shooting.
This room wasn't completely boring due to the wainscotting, but we needed some more visual interest and a pop of color. We found this old loveseat in the ballroom. (Interesting point of fact: This was shot in the same hotel that they shot No Country For Old Men.)
One of the things I enjoyed about shooting in Taiwan was that, even though the buildings looked run down, there were oftentimes enough decorations and elements hanging around that made it look interesting in camera.
This shoot: https://www.bbc.com/storyworks/technologys-golden-age/niantic-pokemon-go-taiwan
Company: https://www.lashfilms.com/
Thrift stores are great for finding cheap items to toss into the background or to dress up a boring location. I would say after all that you need to focus on wardrobe. Think of your background color pallet when choosing outfits for your talent.
The last element in the mix is talent. Try to find talent that is interesting, beautiful, or better yet, actually talented. If you have a mix of all three, you probably can't afford that person.
Check out the aforementioned Danny Gevirtz here: https://www.youtube.com/@DannyGevirtz