Keep the garden vertical. That's why it's good to look for shrubs and trees that max out interest as they grow up, not out. Try dwarf varieties for a small backyard, as well as more columnar evergreens (bonus—they boost wintertime interest, too).
"Idea for the side of the house Left side facing the house"Emerald Green Arborvitae ( Thuja ) -- My main hedges on the N and E of house. Corners I have allowed them to get way tall, cannot climb a ladder to trim anymore.