A Sampler of Digital Techniques
Sunflower Layers
Layers: Many art programs allow you to separate different parts of the image. Here, the lines are on top, the color is in the middle, and the blue background is the bottom layer.

You can add many more layers, as needed.

You can draw, erase, adjust colors, or make other changes on a layer without affecting the rest of the image.

Drawing and Painting: I use a digitizing pen and tablet to draw with instead of a mouse.
Wacom Tablet
As you draw on the tablet, the lines appear on the monitor.
Scanning: This is a real seashell that I scanned in. You can scan almost anything that will fit on the scanner bed (or scan a photograph of it.)
To the left are just a few of the endless textures artists can create to use in their work.
Texture Samples