Always Color in a Consistent Direction. This is my first tip. It will make a bigger impact on the end result than anything else and any age can use it! The changes in direction, shown on the red kidney below, on the left side, are what make it look sloppy, even though I carefully stayed in the lines. Coloring in a consistent direction, as seen on the other kidney, is easier on the eyes and ends up looking very tidy!
In fact, taking a crayon or colored pencil to paper is a therapy method that dates back to the early 20th century _ though it seems people are just starting to rediscover its benefits. So how exactly does something as simple and seemingly childlike as filling in the lines lend itself to combating adult amounts of stress?