Hilly terrain might sometimes be a challenge but it is a great opportunity to create even better gardens than can be done on all level ground. I love the way your land slopes upward. One can see a lot more of the plantings all from one spot.
I do lots of terraces because I had tried to do gardens in many of my steeper spots without them and it just did not work. So I have been putting in lots of hardscape for the past three years. Very expensive but it will all outlast me!