I uses the extension called 'Ar Base' which help me look for the light and reflection on the object and will help me used for develop in the following step.

I change the appearance  control for it to show only the outline and I will marker render it after in procreate.

I've added themarker as always. This time it make the work easier because I have cast the shapes from onshape so I don't need to fineline it.

I also added the shadow as always by looking at which way light cast on the object. I uses Soft dirty airbrush  for the shadow.

I have added the linking box at the back to make us feel that the object is hovering above the wall. As you can see I have picked the colour that is very earth tones to make the shape more stand out.