Mixed Media Thursday: From sketch to painting

I've always wondered why artists did like a whole detailed mini sketch of a subject matter before working on the actual piece even though sometimes the final piece doesn't even look anything like the sketch.  So I decided to give it a go to see what I can learn from the process.

First I started with doing the background of my mixed media painting - the usual layering of mediums in various different colours until I had a pleasing result.

Then I went into my sketchbook for the sketch of an eye I did recently in coloured pencils and paint markers.

Using the sketch as a guide, I drew in the shape of the eye with a water brush pen filled with ink. I like using ink as opposed to paints at this sketch stage because the ink has more "open" time and I can just clean it off with a wet wipe/rag if I made a mistake.

Now I know why artists take the time to do a detailed sketch first because it really helps to save time on the actual piece. I actually got this eye done in one sitting...under three hours...because I didn't have to fiddle with getting the eye shape/angles right.

I really like how the final piece turned out. Here it is on my gallery wall. It measures 20 by 20 inches.

What do you think?