How do I create my digital illustration?

Everything is done digitally from base drawing to the final coloring.

Here is the process:
First, I draw directly on computer using Wacom Tablet.
I use a thick black line pen I created my own.

Then I change the color line using Photoshop channel mask.

After changing color line to brown in this case, I start coloring around the line.
Here is the base colored image.

Then I place different texture or change the image through filter depending on how I want my final image to appear.

I create this textire separately and past into my image.

And this is the finished image.