A good garden design has a clear structure, suits how you actually use the space, and looks decent in every season, not just June. Structure means defined bed lines, at least one focal point, and a deliberate path for the eye and the feet. Usefulness means the dining spot is near the kitchen door and the play area is visible from the house.
A few measurable habits separate good designs from plant collections: repeat the same plant in groups of three or five instead of buying singles, keep roughly a third of the planting evergreen for winter, and match hardscape materials to the house. Restraint matters more than budget. Five plant varieties used well beat twenty used once.
Before committing, test your ideas on a photo of the real space with AI landscape design and see which version holds together.