Nice sketch. With regards to deep-sky sketches I have tried different techniques including using black paper with white pencils, black paper with colored pencils, and white paper with lead pencils.
Also I have tried white paper with lead pencils and then inverted it once scanned into the computer.
In some ways I find using black paper with white pencils at the eyepiece easier because it matches the view through the eyepiece.
On the other hand I find that erase marks can show up more easily on black paper than white paper. So I need to try and clean them up after I scan the sketch in.
Either way it can be a nice way to spend a night under the stars. Unlike when sketching a planet or the Moon where you need to record the detail quickly deep-sky objects don't move, and you can observe and record more detail again on subsequent nights to finish the sketch.
Here are some of the deep-sky objects I have sketched: