Drawing Curved and Straight Lines
Use the Point to Point tool to draw lines and then create curves
by editing the line nodes.
To draw using curved and straight lines:
From the Pen tool’s Tool
Options palette, choose Point to Point 
.
Click and drag at the start point.
When the direction of your line is correct, release the mouse button.
For the next node:
To create a straight
line, click where you want the next node.
To create a curved
line, click and drag. When the curve is the right shape, release the mouse
button.
Add additional nodes, clicking
for a straight segments or clicking and dragging for curved segments.
Changing
Curves and Lines
Creating
Custom Line Shapes
Drawing
Lines and Custom Shapes
Setting Line
Options