Freedraw

How do I make freedraw annotations?

Freedraw annotations can be created by clicking on Freedraw on the Toolbar (or using the keybind F). Then, head over to the canvas and perform left click + drag over the outline of the region you wish to annotate. Once the mouse is released, a polygon will be formed. You may continue drawing or press y to switch between erasure and drawing modes.
Once satisfied, you may end the annotation process by pressing the Space key. If you do not wish to commit your annotation, you may abort it by pressing the esc key.

How do I see other annotation tools?

Look at Annotation Tools for other tools.