Welcome. I used the actual skyline of Indianapolis (I researched your location). This really localizes it for your market. One concern is that our rules do not allow the use of the KW logo until after the contest is over. Not sure why some are using it. My design does not contain it for that reason. You are free to have it added after the fact in accordance with your franchise agreement with KW.
I have done a lot of work for KW agents here. In addition to the ideas submitted here, feel free to take a look at other KW agents who have selected my work here as they may inspire an idea for your design as well.