Remember what your elementary school teachers told you over and over? "Neatness Counts!" This adage applies especially well to TaskMaps. A map that is neat and uncluttered, perhaps even aesthetically pleasing, will convey far more information than a cluttered one. Your audience will grasp the overall picture and the process details much more readily.
Use Labels on Connectors to describe verbally where the process goes next or has come from. Knowing that task C03 leads to D01 is fine, but a concise Label makes the reader that much more comfortable.
Try hard to avoid have Task Link lines cross each other. There is almost always a way to arrange tasks so that lines don't have to cross. Experiment with less obvious placement if you don't succeed at first. Also, see the tip below about on-page Connectors.
Keep the process flow simple and consistent, and try to avoid direction changes. For many TaskMap readers, right-to-left and top-to-bottom is the easiest to follow.
Consider using a Connector to refer to a Task on the same page. While the most common use of Connectors is to link to Tasks on another page, occasionally a complex drawing that doesn't require another page can be simplified somewhat by an on-page Connector.
Place Start shapes and Connectors coming into a TaskMap on the left margin of the diagram. Place End shapes and Connectors leaving a TaskMap on the right margin of the diagram. These visual cues make it easy to discern the inputs and outputs of a TaskMap.