The many shapes of different brushes in Photoshop make it possible to obtain interesting effects.
Choosing a brush
To change brush it is enough to click on the small arrow located on the right of the "shape" of brush and to select another one from the window that opens.
Loading new brushes
Photoshop has several preset sets of brushes. To load them and make them usable, click on the "arrow" located in top on the right of the window with brushes, then to choose "Load brushes". The files containing the brushes have the extension .abr and are generally located in the directory "brushes" of Photoshop.
Other options are available in the same menu, making it possible to create, change, save etc. the sets of brushes.
Modifying a brush
To modify an existing brush, right click on on the icon that shows the shape of the brush . A window appears showing several options. Note: these options can vary depending on the brushes' and tools' used.
You can in give a name to the brush, choose the diameter, hardness, roundness and the (angle).
The spacing
The spacing of the dots drwn by the brus depends on the speed with which you move the bursh around. (top slow, under fast ).
When yo enable the checkbox next to spacing, you can give the brush a fixed spacing.
Tip:
To draw a straight line you can click the startpoint while holding the SHIFT-key and then click at the end point. As long as you hold the SHIFT-key a straight line will be drawn from the last point to the next point where you click.