Update! Click here (20 Brush and Painting Tool Shortcuts in Photoshop CC) to see twenty of my favorite tips related to brushes and painting in Photoshop CC in a single post.
In order to create a “dotted” line instead of a solid paint stroke, display the brushes panel and click on Brush Tip Shape. Drag the Spacing slider to the right until the desired amount of space falls between each stroke. Because this simply changes the tip shape of the brush it can then be used with other painting tools such as the Pencil (great for squares), History, Eraser and Stamp tools, as well as Dodge, Burn and Sponge, and Blur, Sharpen and Smudge tools.