The First thing to do is to load a scene or object, or even just a basic shape (square, circle.... so on)
The next thing to do would be to get into the Render settings.
( Ctrl + B ) Or Render > Render Settings
Then click on the Effects Tab on the left side. After this you should click on the Tab in the upper right and roll down
to Sketch and Toon
This is the Area where you can pick many diffrent options for what the sketch will look like... such as the Line thickness
or even the main colors to use.
This is the what the Defult Settings will look like... Expect larger ammounts of polygons/edges to take
extra time to render.