If your yard is on a slope, it is important to take that into account when designing your landscape. In most cases, it is not worth excavating and flattening the slope as doing so is quite expensive and may compromise the stability of your home's foundation. Instead, you should focus on designing a landscape that works with the slope. Here are some ideas to guide you.
Use steps as the focal point.
Consider having a set of steps put into the middle of the slope. These can serve as the focal point, and they are also functional. People can walk up them, which will reduce wear and tear on the grass on your slope. You do not have to go with traditional concrete stairs, although that is one option. A series of large, unique stones embedded into the slope can work as stairs. Or, you can have some stairs made with concrete pavers.
Create a waterfall.
If you live in a wetter climate, consider having a waterfall built into your slope. This won't be a traditional waterfall because there won't be water running down it all of the time. What you can do, however, is put a rocky strip down the slope and create one substantial drop-off in the middle of the rocky strip. When it rains, water will drain off the slope via this rocky strip, and the effect will make it look like a waterfall. This design also helps keep the rest of your slope dry, since the water will all flow into this one area.
Plant flowers of different heights.
When it comes time to select plants for your yard, consider choosing some taller flowers for the top of the slope and progressively shorter flowers for further down the slope. This arrangement helps ensure you can always see up the slope, and it also ensures none of the flowers are out of your line of vision. Some good tall flowers to include are daffodils, tulips, and black-eyed Susans. Some shorter flowers to use include pansies, petunias, and marigolds. Make sure you pack the soil tightly around the flowers as it has a tendency to get rinsed away on the slope.
If your yard is on a slope, consider implementing one or more of the landscaping ideas above. Talk to a landscape design contractor for more feedback. They may have some additional suggestions that are better suited to your unique yard.