After entering the free hand drawing mode, you can define a set of drawings by moving the mouse.
To start, click at a point you want to start your drawing.
Move the mouse to draw.
Click again to finish this specific drawing.
Repeat the operation if necessary, to add more drawings
When satisfied, press Save. The set of drawings is now one drawing object, stored in the base.
After a drawing has been saved, it can be edited.
Hover the mouse over a drawing until the color change. After a 0.5 sec delay (can be set in the Preferences, Lines tab), a panel pops up as shown below.
You can move, resize, rotate, copy or delete the symbol.
Note the smoothing checkbox. By default, points are interpolated to look nicer. You, however, lose a little bit of accuracy doing so. You can toggle the smoothing on/off for each of the drawings independently.
You can insert and/or create predefined symbols.