My client's request other than a fountain which is a blue glazed olive jar, is that I put Colicassia esculenta 'Black Magic' somewhere in the garden.
I still render presentation drawings for clients by hand but I use a color add on for my CAD program because it's fast for down and dirty color studies. At the point I'm using it I don't pay much (read some) attention to texture because the choices the program offers are limited--hence the Heuchera x 'Obsidian' in the drawing really looks more like stone than a plant! These quick visual thoughts are working drawings and I know what the plants look like, so the color studies are more for the ratio of one color/texture to the adjacent ones and the rhythmic flow of the planting design. I change my mind often when designing planting plans--it's not always intuitive for me. Spatial relationships and human interation with and through space are much easier.
The very simple plant list includes: