protected override void WriteXmlElements( 
   XmlWriter writer
)

{
  //Note: on the QueuedTask
  //Place symbol on the layout
  MapPoint location = MapPointBuilderEx.CreateMapPoint(new Coordinate2D(9, 1));

  //specify a symbol
  var pt_symbol = SymbolFactory.Instance.ConstructPointSymbol(
                        ColorFactory.Instance.GreenRGB);

  //create a CIMGraphic 
  var graphic = new CIMPointGraphic()
  {
    Symbol = pt_symbol.MakeSymbolReference(),
    Location = location //center of map
  };
  //Or use GraphicFactory
  var graphicFactory = GraphicFactory.Instance.CreateSimpleGraphic(location, pt_symbol);

  ElementFactory.Instance.CreateGraphicElement(layout, graphic);
  ElementFactory.Instance.CreateGraphicElement(layout, graphicFactory);
}

{
  //Note: Must be on QueuedTask.Run

  //Place symbol on the layout
  MapPoint point = MapPointBuilderEx.CreateMapPoint(new Coordinate2D(9, 1));

  //specify a symbol
  var pt_symbol = SymbolFactory.Instance.ConstructPointSymbol(
                        ColorFactory.Instance.GreenRGB);

  //create a CIMGraphic 
  var graphic = new CIMGraphicElement()
  {
    Graphic = new CIMPointGraphic()
    {
      Symbol = pt_symbol.MakeSymbolReference(),
      Location = point //A point in the layout
    }
  };
  ElementFactory.Instance.CreateElement(layout, graphic);
}