Super easy, we just throw 1 cup of oats and 4 cups of water in the blender, blend it for ~45 seconds and put it through a cheesecloth bag a time or two. I like to throw a little maple syrup in there to sweeten it up a bit.

As another commentor said, you can soak the oats overnight, and that makes it better, but most of our oat milk is for my toddler and I’m not prepared