Measure the whole space and sketch possible design options. Draw a large area that will be the core space of the yard, such as a large rectangle. Section off odd parts of the yard with a curved border. Plan to use a small retaining wall, border of pebbles or row of small bushes to define the curved borders. Transfer the design to graph paper for further fine-tuning.
Use oddly shaped sections for various family projects or activities. Build a carport or garage in a distant corner of the yard, for example. Install a children's swing set in one of these spaces. Put in a small orchard of miniature fruit trees or create a lawn space for a pet's house.
Plan the core section of the yard in further detail. Plant grass and create a walkway or two through the backyard. Install a bench, concrete patio with roof cover or small swimming pool. Use a mixture of small bushes and flowering plants in beds next to the house.
Use fencing and plants to soften property lines. Add a picket fence to draw attention to the backyard border between the core space and a distant section, for example. Plant a row of shrubs or install tall flowers to disguise a long section of yard that is off to one side. Install a fence that curves in an interesting fashion to visually cut off a jagged part of the yard.
Buy stone materials to clearly call attention to odd sections of the yard. Direct attention to distant parts of a yard by filling them with white pebbles. Use outdoor statues or large concrete containers of ivy and other plants to make the odd section stand out. Decorate your yard this way if, for example, an elongated area in the back leads to a lake or walking trail.