Tutsplus - Creating Conceptual Illustrations

In this course you will learn how to create a stunning conceptual illustration for both editorial and commercial use from a hand-drawn sketch, using a combination of Adobe Illustrator and Adobe Photoshop. Throughout the course you will create realistic symbols using a combination of the Pathfinder panel, Gradient Tool, strokes, reflecting objects and multiple shape tools and the Pen Tool among others. You will learn how to export the symbols that you'll be creating in Adobe Illustrator as layered PSD files to maintain maximum editability when we cross over into Adobe Photoshop. Once in Photoshop, we'll construct the final composition as per the initial sketch, finishing up with a creative conceptual illustration.

http://design.tutsplus.com/courses/creating-conceptual-illustrations