Adding more letterbox caches in the area. There just aren't enough around, and they're relatively easy to place (if you have stamps to put in them) and find.
For new cachers, a letterbox cache has a stamp inside. It is to be left in the cache. If you participate in Letterboxing, you carry your own stamp and ink pad. When you find a letterbox cache, you would stamp your stamp in the cache log book, and stamp the cache's stamp in your personal book. Easy Peasy! If you aren't into Letterboxing, just sign the log and get a different type of cache icon!