Here is my approach to my iguana design. It started with reference photos that I took while I was in Cuba. Then I simplified the the picture to a do-able design for teaching kids of a variety of ages and abilities. The result is the oil pastel drawing.
For my more refined illustration of the project, I went back to my reference photos, keeping in mind that I wanted to imply a quality similar to the original design taught in class, especially with the use of color.
Then I made a quick sketch with a Sharpie pen in my sketchbook. I like Sharpies because they allow me to rapidly get ideas down.
Using my Sharpie sketch as a direct reference, I quickly blocked in the basic shapes of the iguana in his environment. In two steps, I laid down the colors for the picture.
In the final step I took about an hour to
render the light and shadow of the image, and added some line to give clarity to the picture. The trick was not overdoing the technique and trying to hold back a little to not draw every single detail. Less is sometimes more in this approach.