It pays to send a little time setting up the brush options, as this determines the way they appear on our screen. Choose edit>preferences>display&cursors in Photoshop 6or file>preferences>display&cursors in Photoshop 5. This dialogue box gives us several options, using the brush size from the painting cursors and precise from the other cursors will give us the most accurate brushes and cursors to use.
Standard Cursors -Default
Airbrush The Airbrush tool sprays soft defused lines ideal for blending into an image or building up colours. It uses a softer brushes by default and requires lighter pressure. Unlike the paintbrush the airbrush applies a stream of coloured droplets as you click the mouse.
Paintbrush The paintbrush paint in softlines but not so defused as the Airbrush. It also paints in an antialiased line that blends with its background.
Pencil Tool The Pencil tool produces hard-edged lines, ideal for drawing.
To draw a straight line using the paintbrush, pencil tool or airbrush, click a starting point in the image. Then hold down shift and click an ending point.