I am a big fan of sketch rendering in Vectorworks, not because it tricks your client into thinking that you have drawn by hand, but because it allows the client to see where you are in the design process. However, the sketch rendering styles that ship with Vectorworks do not suit my own handwriting style, so I usually edit these. First, apply sketch rendering to your view or viewport. Then go to the Render Settings and choose Sketch Options… This will open a dialog box for you to choose sketch rendering settings from your default content, or you can click on the Edit… button to choose the settings you want. In the editing settings you can choose several options to make this sketch rendering style similar to your own and drawing technique.
You can apply sketch rendering to the entire view, but you can also apply sketch rendering object by object. If you select an object, then go to the Render pane of the Object Info pallete, you can choose what sketch style you want to apply to each object. You will only see the difference when you apply sketch rendering to the entire scene.