My entire art style is the opposite of time efficiency ;-;
My line art takes a bajillion years each update (about 70% of the time I spend on the episode overall) and the way I chose to draw hair and fabric is especially time-consuming because I feel compelled to draw (and then have to shade) each individual fold and clump of hair. Take this panel:
I'm also a sucker for multiple light sources and several layers of shading. I think it adds a lot of depth and looks great, but this part of the process also takes a bajillion years.
I also used to kill myself trying to get the anatomy perfect in every panel by having an entire new layer of body construction lines over my thumbnail and before final line art, but I ditched that after episode 3, and fortunately, I don't think it hurt the quality of my art.
Last inefficient thing I can think of is having to modify my color palette in every new episode because the setting (and therefore lighting) changes, making some episodes' palette more warm or cool, lighter or darker, than others.
For all this, I think it shows that I'm still a new comic creator in the process of learning.
I can't bring myself to sacrifice some of these things just yet, but I'm hopeful that I'll become faster with time. One comforting example of that growth taking place is that I'm now able to jump straight from thumbnails to line art and still have good anatomy, and as I memorize my characters' appearances I don't have to check my references so much.
Still... panels like these make me want to rip my hair out sometimes. :'D