How can I make this look more natural/real and clean

Im building a medival styled wooden bridge for walking/mine cart riding. its going over a small lake and will pass over a small piece of land before connecting to main land again. I’m wondering how I can make it look more natural/real. I was also planning to add a large stone support in the middle. I would really appreciate some advice as this is my first ever time trying to build seriously in a world.