For best results, remove the coloring book page from the book before painting so the paint doesn't warp the pages below or seep through. Using removable tape, affix it to a rigid work surface to prevent buckling of the page as you paint.
Make it a zentangle. By using ink, you can "color" in the page using different pen strokes like hatching and cross hatching and tiny patterns to create an intricate coloring wonderland. Before you know it, the page will completely change character, becoming almost like a collaborative work between you and the coloring book page illustrator.