Here is a simple breakdown of my process. Im mostly recording this for my own benefit to track how my techniques change over time so I apologize if it's not too thorough.
Step 1: Pencil Sketch. I don't really enjoy sketching in the computer with a tablet. I don't have a lot of control and can't make changes as quickly as on paper and with a shitty, bitten or picked off eraser. I like the messiness of it.
Step 2: Line art in Illustrator. I take the sketch into illustrator by literally dropping it in. I set the opacity to around 30% on a separate layer and go over it with the pen tool. It's a long process but I like to be attentive with my lines and illustrator let's me easily control line width and go back to make changes online photoshop whereas id have to go back, erase, and redraw it. It's a preference and the way I learned illustrator...
Step 3: Finished Line art/Line coloring. After most of the lines are configured to the width and style I like, I go in and color some of the lines so they're not all stark black. I like to make sure proportions are right and all the details are there before I move into color
Step 4: I won't go too much into detail on color because I'm still testing different methods and Im a rookie when it comes to different shortcuts. Im really just trying to get a handle on rendering overall at this point so my layer organization is a cluster fuck. Ill get my shit together sometime but coloring takes a brunt of the time. Im starting to move away from stark vector drawings and combining both illustrator and photoshop - which is exciting!