Landscape design is a plan. It may be simple or complex. At a minimum, the main elements of the landscape must be sketched out. This includes such things as lawn areas, shrub planting areas, water features, etc.
Generally, a more detailed sketch works well for more involved landscapes, especially if the designer oversees the installation.
We commonly manage installation as it increases efficiency and minimizes expense. A complete scale drawing is advised on more complex and detailed landscapes. You may prefer this choice since it gives you a better understanding of the final result. A detailed list of appropriate plants is quite helpful since this allows you to research each plant online to see what they look like and to review their characteristics.