Get outdoors and find exciting new places to photograph. You can find information on Ohio trails at websites like Neo Naturalist, while the Ohio Division of Natural Areas and Preserves has a website dedicated to information on Ohio nature preserves. There you can find maps to sanctuaries like Sanctuary Marsh, a popular birdwatching spot. You should also look for places that were once urban and are becoming wild again for even more unique glimpses of nature.
Consider joining a nature appreciation group, such as birdwatching groups, adventure groups or hiking clubs to find new places to photograph. Besides locations, you may even find new subjects, such as an obscure endemic animal. These groups will also help you learn more about particular animals or areas such as the best times and places to photograph. You can find the Southern Ohio Wildlife Photography club as well as other photography and nature clubs online.
Take a class in nature photography at an Ohio college or University. If there isn't one near you, consider a regular photography or digital photography class and ask the instructor to help you improve your nature photographs. If you are already an accomplished photographer, consider taking a walking class or an art class that takes field trips to develop your eye and find new locations to photograph.
Seasons can produce shocking changes in a location and the animals that visit it. Visit a favorite spot every season and document how it changes. Look for things like changing colors, damage --burnt down trees, lightning strikes---or how animals have adapted to change. You can even do this over years and show how mankind encroaches on nature over time. The Shawnee state forest is an excellent location for winter landscape photography as well as for bird photography in the spring. At Brown's Lake Bog you can find four-toed salamanders and a variety of flowers including the rose pogonia and grass pink orchids.