You're using negative space pretty well, filling up the canvas isn't necessary which is what i'm trying to incorporate. You can also have dark spots in certain areas that are out of the norm to have that professional feel. Also instead of big soft brushes, tend to stick to a few clicks of smaller ones around the focal. For lighting around edge, i usually tend to disregard that and focus on shadows instead. Fractals are kind of in atm so it looks modern, but it still has that oldschool vibe which you kind of wanna ditch, To do this i suggest you pick up abstract resources things like abstract brushes, textures, and certain c4ds.