The Freehand Tool will probably feel familiar to you immediately. At first, your lines may appear rough, but you can always refine them using their nodes and the Shape Tool. As you continue to practice with the Freehand Tool, drawing will come naturally.
Select the Freehand Tool (see Figure 7.1). The pointer changes to a cross-hair with a tiny squiggle attached to it.
Click where you want the line to begin.
Click where you want the line to end (Figure 7.2).
Figure 7.2. To create a straight line, click to start the line and click where you want it to end.