Stagger three to five trees along the wall or fence. Plant several outside the enclosure if possible, or plant vines or climbing ornamentals so that they overhang on the inside.
Set aside more space for planting inside the courtyard where there is enough light and to mark prominent places such as an outside entry to the courtyard. Screen an undesirable view or frame a desirable one with the planted beds. Use lattice screens to shield utility areas from view.
Plant a mix of shrubs and flowers with varying heights and small specimen trees in the beds. Organize furniture facing the aesthetically pleasing views. Place small self-contained water features near the courtyard entry and by the seating arrangement.