Take your time with one drawing.
Keep going back and working on it.
Erase the lines you don't like, draw new ones in place of them, etc
Envision what the viewer wants to see, and put that on paper.
Try to figure out which techniques make what look like what. Don't draw anything, instead, try shading, or going back to basic shapes and creating form with texture or color
There's a lot to be said here. Set a course and stick with it, or learn multiple styles vs creating your own style
generally a really good drawing is "done" when changing or covering anything "ruins" it
Conversely/related
I've recently (finally) found that quickly sketching a total garbage version of the art and then "cleaning it up" works incredibly well
Ideally everybody is excited and you find yourself surprised by your own work when you go back and look at it the next day
Idk