I actually use a very analog process to get all my pictures into my blog as well as my book.
I start by drawing my pictures, first in pencil and then outlining them with a micron ink marker, selecting a thickness depending on the effect on trying to create.
I then assemble these pictures into a composite form by cutting out the images and placing them next to each other.
I make sure to keep my images organized catalog so that I can quickly lay out new composite images, notice the comic bookbags used to sort my images by different themes.
Images are scanned and cleaned up into digital form.
Finally, I lay out the image using PowerPoint (I know design professionals will be groaning at this one) and save it as an image.