Simple sketch with ballpen on a regular A4 printing paper that I sneaked out of the local printers at my college (our little secret.)

I wanted to go with a pretty clear seperation of a strong direct light that casts clear shadowshapes. That is why I mapped out the shadow shapes using a multiply layer first.

Added the local colors (half tones) under the multiply layer. The layer mode was set on normal. The multiply layer seems to work like you would pick up a pair of sunglasses and put that on top of all the colors you see. It creates the effect of darkening everything and you are able to choose the color and darkness of this effect yourself by switching between the hue or value. This is the very reason why it looks like there is a shadow casted upon the painting since now we have created two worlds, one in the lighter side called the world of light and one on the darker side that we can call the world of shadow (also known as ambient light since it's really just a diffused light that still is able to cast it's own shadows).

Alright, I could ramble about this forever, So let's get on to the next step and keep it more simple and short this time..

I added a warm light on top of all the layers combined by adding a yellowish color to the light areas. 

Rendered out the final details and added some occlusion shadows, reflected light and ambient light here and there inside the shadow shapes.

et voila, a cute little samurai themed inn.

Thank you for watching.