I have been coloring mandalas from Michelle Normand. Her mandala coloring site is http://www.30minutemandalas.com/
There are four free mandalas to color and 2 coloring books for sale.
I first got my start in mandalas from coloring mandalas. Later I moved on to digital mandalas. If you are interested in making mandalas coloring mandalas is a good place to start.
The first mandalas I colored were with marker, but this time I wanted to try digital coloring. These mandalas work good with digital coloring because the large spaces leave room to show off special effects.
This first one is where I started. I am very drawn to the combination of black and dark greens with lighter green as an accent. I replaced the thick black outlines with dark brown to give it a dark forest feel.
I reversed one of my dark gothic crosses, played around for a little bit and got these two icy crosses.
I reversed icy blue cross, tweaked it a bit and came up with two fire theme crosses. Two themes seem to come up often for me. One is the dark forest, which I intentionally started with. The other is fire, where the series ended up.
I often use my mandalas as an intuitive device. They are a way to express what is in my inner self. I was surprised to discover that coloring in mandalas someone else has made works just as well.