sketch
I usually scan my sketches (600DPI) so that I can process them through Photoshop without losing quality.
I used Wacom Intuous 6 x 8 graphics. There are many geniuses who can draw mice, but no one can draw sharks.
First, create the outline of the shark using the Pen Tool. After painting, I turn on the transparency and copy layers. Hide the original shark shape layer and use it as a mask.
I used greyscale to render out the details and subsequent colors. This is a very useful technique that allows you to focus on the arrangement of your tones without getting distracted by the colors themselves. I filled the shark shape with a medium gray color, then duplicated the layer and moved it to the top. Give it a multiply opacity of 10-20%. This can give people a vague feeling.
In the next section we introduce rendering. See how to make the shark in the sketch appear three-dimensional.