1. In Manga Studio, I start with a very rough thumbnail sketch with big fat pencils. The fat pencils force me to keep the sketch loose without getting too caught up in the details.
2. Final sketch. Now I go back and do a more detailed sketch, working out the the body, clothing, and props. I used perspective rulers to line up the shelves and ladder.
3. Inking. I use a variable-width inking brush for the characters and a constant-width brush for hard things on vector layers. I use lots of different layers for different parts, which makes it easier to overdraw and erase as needed. I also went ahead of inked the shape for the eyelashes because the brush stablization in Manga Studio makes it a lot easier than doing it in Photoshop later. I exported the characters and the shelves on separate layers.
4. I didn't want to have to draw and color hundreds of books so, instead, I drew sixteen books and turned them into a random-book brush in Manga Studio. Then I used that brush to quickly create several rows of books as seen straight-on. Then I brought those rows of books into Photoshop and used transform/distort to give them just a little bit of perspective on the back shelves.
5. The middle shelves go some basic, simple shading on a layer above the back shelves.
6. I used transform/distort again on more rows of books to add the spines of the books to the middle shelves.
7. Since these books are at a different angle, I had to add in the sides of some of the books, which I did by sampling colors from the spines and painting them in by hand. It took some extra work but it was a lot less work than it would be to simply draw every book individually.
8. I convert the imported lines for the characters to a folder with a mask and put a solid black layer in the folder. (CTRL-click RGB in the Channels tab, invert the selection, create a mask from the selection.) This will come in handy later when I color the linework. Then I create another folder and start creating the basic color blocking. I like to do all my color blocking by making a folder and then filling it with different solid color layers for each section of color, whch makes it easy to change a color later. This is a very fussy way to do it and it's probably much simpler to just fill a single raster layer with flat colors.
9. Form shading. I create a dark brown solid color layer (linear burn) and start painting in the basic form shading with a soft airbrush. For the hair, I used color burn for richer shading and I used a variable-width soft airbrush to smudge detail into the shadows, picking up the shape of the hairs.
10. Cast shadows. I make a new dark brown layer set to multiply and start painting in the cast shadows with soft brush, using a smaller brush in places where the object casting the shadow is closer to the thing the shadow is on.
11. Backlight. A very desaturate pale pink solid color layer (screen) painted with a soft airbrush. When I combine it with the form shading, backlighting really makes the characters pop. I don't use any backlight on non-reflective objects.
12. Shiny. I used a solid white layer for the primary shine, which is on the underside since the light is coming from below, and painted spots and streaks using a hard variable-width brush. After painting all the shine, I use the cast shadow layer to make a selection and delete the shine from anywhere covered by shadow.
13. For the blush, I add in a light red layer, airbrushing just on the same area as the skin for the cheeks and other cheeks. I use the same method to add color for the eyeshadow and the blush lines.
14. Colored linework. Going back to the linework folder, I started adding new solid color layers, using the mask to paint the color of the linework. Since the new layers are inside a folder with a mask defining the linework, I don't have to be very precise when coloring the lines. I always add new color layers below the ones I already did so that I can be sloppy in the areas that are already covered by colored linework.
15. Eyelashes are done with a folder containing a solid grey layer and a solid black layer. Using the lashes I made earlier with a variable width brush, I add a few thin streaks on the grey layer mask to add depth to the lashes and soften the look with a few strokes of a soft airbrush.
16. Eyeglasses. I added a semi-transparent white layer above the linework, for the glass in the eyeglasses.
17. Finally, I added a heavy blur to the most distant shelves and added a brightness/contrast adjustment layer for all of the shelves, making them more desaturate and just a little bit darker, so that the characters would pop forward a little bit.